NCI Dictionary of Cancer Terms

393 results found for: H

H and E staining: (… STAY-ning); A common laboratory method that uses two dyes called hematoxylin and eosin that make it easier to see different parts of the cell under a microscope. Hematoxylin shows the ribosomes, chromatin (genetic material) within the nucleus, and other structures as a deep blue-purple color. Eosin shows the cytoplasm, collagen, connective tissue, and other structures that surround and support the cell as an orange-pink-red color. H and E staining helps identify different types of cells and tissues and provides important information about the pattern, shape, and structure of cells in a tissue sample. It is used to help diagnose diseases, such as cancer. Also called hematoxylin and eosin staining.
H. pylori: (… py-LOR-ee); A type of bacterium that causes inflammation and ulcers in the stomach or small intestine. People with H. pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma. Also called Helicobacter pylori.
hA20: A substance being studied in the treatment of several types of lymphoma. It binds to the protein CD20, which is found on B cells (a type of immune system cell) and some types of lymphoma cells. This causes the immune system to kill the cancer cells. hA20 is a type of monoclonal antibody. Also called HCD20, IMMU-106, and veltuzumab.
HAART: Treatment that uses a combination of three or more drugs to treat HIV infection. HAART stops the virus from making copies of itself in the body. This may lessen the damage to the immune system caused by HIV and may slow down the development of AIDS. It may also help prevent transmission of HIV to others, including from mother to child during birth. Also called cART, combination antiretroviral therapy, and highly active antiretroviral therapy.
hair follicle: (… FAH-lih-kul); A shaft or opening on the surface of the skin through which hair grows.
hairy cell leukemia: (HAYR-ee sel loo-KEE-mee-uh); A rare type of leukemia in which abnormal B-lymphocytes (a type of white blood cell) are present in the bone marrow, spleen, and peripheral blood. When viewed under a microscope, these cells appear to be covered with tiny hair-like projections.
Halaven: (HA-lih-ven); A drug used to treat certain types of breast cancer and liposarcoma (a type of soft tissue sarcoma) that have already been treated with other anticancer drugs. It is also being studied in the treatment of other types of cancer. Halaven blocks cell growth by stopping cell division and may kill cancer cells. It is a type of antimicrotubule agent. Also called E7389 and eribulin mesylate.
Haldol: (HAL-dol); A drug used to treat certain mental and neurological disorders. It is also being studied in the treatment of nausea and vomiting caused by some cancer treatments. It is a type of antiemetic and a type of antipsychotic. Also called haloperidol.
half-sibling: (haf-SIB-ling); A person’s brother or sister who has one parent in common.
hallucination: (huh-LOO-sih-NAY-shun); A sight, sound, smell, taste, or touch that a person believes to be real but is not real. Hallucinations can be caused by nervous system disease, certain drugs, or mental disorders.
halofuginone hydrobromide: (HA-loh-FYOO-jih-none HY-droh-BROH-mide); A substance that is being studied for its ability to slow the growth of connective tissue and to prevent the growth of new blood vessels that tumors need to grow. It is a type of quinazolinone alkaloid and a type of antiangiogenesis agent.
haloperidol: (ha-loh-PAYR-ih-dol); A drug used to treat certain mental and neurological disorders. It is also being studied in the treatment of nausea and vomiting caused by some cancer treatments. It is a type of antiemetic and a type of antipsychotic. Also called Haldol.
Halsted radical mastectomy: (HAWL-sted RA-dih-kul ma-STEK-toh-mee); Surgery to remove the whole breast, all of the lymph nodes under the arm, and the chest wall muscles under the breast. For many years, Halsted radical mastectomy was the type of breast cancer surgery used most often, but it is rarely used now. It may be used only when breast cancer has spread to the chest wall muscles. Also called radical mastectomy.
hamartoma: (HA-mar-TOH-muh); A benign (not cancer) growth made up of an abnormal mixture of cells and tissues normally found in the area of the body where the growth occurs.
hand-foot syndrome: (... SIN-drome); A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also called palmar-plantar erythrodysesthesia.
haploidentical donor: (hap-loh-i-DEN-tih-kul DOH-ner); A term used to describe a tissue donor whose HLA tissue type partially matches (usually 50%) the HLA tissue type of a person receiving a stem cell or organ transplant. HLAs are a set of cell surface markers found on a person’s cells and tissues that play an important role in the body’s immune response to foreign substances. Before someone receives a transplant, their HLA tissue type will be matched with that of a potential donor. A haploidentical donor, such as a parent, child, or sibling, may be used in a stem cell or organ transplant when a fully or closely matched donor is not available.
happy major: (HA-pee MAY-jer); A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. The scientific name is Arctium lappa. Also called burdock and lappa.
hard palate: (... PAL-et); The front, bony part of the roof of the mouth.
Hashimoto disease: (HAH-shee-MOH-toh dih-ZEEZ); An autoimmune condition of the thyroid gland (a gland located beneath the larynx). It is caused by the formation of antibodies that attack the thyroid gland and it usually causes hypothyroidism (too little thyroid hormone). Symptoms include fatigue, weight gain, constipation, dry skin, depression, and the inability to exercise. It is more common in females and can run in families. Also called autoimmune thyroiditis and Hashimoto thyroiditis.
Hashimoto thyroiditis: (HAH-shee-MOH-toh thy-roy-DY-tis); An autoimmune condition of the thyroid gland (a gland located beneath the larynx). It is caused by the formation of antibodies that attack the thyroid gland and it usually causes hypothyroidism (too little thyroid hormone). Symptoms include fatigue, weight gain, constipation, dry skin, depression, and the inability to exercise. It is more common in females and can run in families. Also called autoimmune thyroiditis and Hashimoto disease.
hawthorn fruit: (HAW-thorn froot); The fruit of the hawthorn tree or bush. It has been used in some cultures to treat certain medical problems, including heart problems and gastrointestinal problems.
hazard ratio: (HA-zurd RAY-shee-oh); A measure of how often a particular event happens in one group compared to how often it happens in another group, over time. In cancer research, hazard ratios are often used in clinical trials to measure survival at any point in time in a group of patients who have been given a specific treatment compared to a control group given another treatment or a placebo. A hazard ratio of one means that there is no difference in survival between the two groups. A hazard ratio of greater than one or less than one means that survival was better in one of the groups.
HBOC syndrome: (… SIN-drome); An inherited disorder in which the risk of breast cancer (especially before the age of 50) and ovarian cancer is higher than normal. Most cases of HBOC syndrome are caused by certain mutations (changes) in the BRCA1 or the BRCA2 gene. People with HBOC syndrome may also have an increased risk of other types of cancer, including pancreatic cancer, prostate cancer, and melanoma. Also called hereditary breast and ovarian cancer syndrome.
HBV: A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although many patients who are infected with HBV may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. Also called hepatitis B virus.
HCA: A chemical that is formed when meat, poultry, or fish is cooked at high temperatures, such as frying, broiling, and barbecuing. HCAs are carcinogens (substances that may cause cancer). Also called heterocyclic amine.
HCC: A type of cancer that forms in liver cells called hepatocytes. Hepatocytes are the most common cells of the liver, and they carry out most of the functions of the liver.  Factors that may increase a person’s risk of developing HCC include having chronic infection with hepatitis B virus or hepatitis C virus, non-alcoholic steatohepatitis, chronic alcohol use disorder, and cirrhosis. Most adult primary liver cancers are HCCs. Also called hepatocellular carcinoma.
HCD20: A substance being studied in the treatment of several types of lymphoma. It binds to the protein CD20, which is found on B cells (a type of immune system cell) and some types of lymphoma cells. This causes the immune system to kill the cancer cells. HCD20 is a type of monoclonal antibody. Also called hA20, IMMU-106, and veltuzumab.
hCRF: A substance being studied in the treatment of brain cancer. It is made naturally by the hypothalamus (a part of the brain) and can also be made in the laboratory. hCRF may help reduce symptoms caused by edema (swelling) of the brain. It is a type of neurohormone. Also called human corticotropin-releasing factor.
HCT: The amount of whole blood that is made up of red blood cells. It depends on the number and size of red blood cells. A HCT test is usually part of a complete blood count (CBC). It may be used to check for conditions such as anemia, dehydration, malnutrition, and leukemia. Also called hematocrit.
HCV: A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although patients who are infected with HCV may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. These patients may also have an increased risk for certain types of non-Hodgkin lymphoma. Also called hepatitis C virus.
HDAC: An enzyme that removes a small molecule called an acetyl group from histones (proteins found in chromosomes). This changes the way the histones bind to DNA and may affect its activity. HDAC inhibitors are being studied in the treatment of cancer. Also called histone deacetylase.
HDAC inhibitor: (...in-HIH-bih-ter); A substance that causes a chemical change that stops tumor cells from dividing. HDAC inhibitors are being studied in the treatment of cancer. Also called histone deacetylase inhibitor.
HDAC inhibitor SNDX-275: (... in-HIH-bih-ter ...); A substance being studied in the treatment of several types of cancer. It blocks enzymes needed for cell division and may kill cancer cells. It is a type of histone deacetylase (HDAC) inhibitor. Also called entinostat and SNDX-275.
HDGC: A rare, inherited disorder that increases the risk of developing a type of stomach cancer called diffuse gastric cancer. This cancer grows in the lining of the stomach, which causes the lining to become thick and hard. The cancer is also likely to spread to other parts of the body, such as the liver or bone. Women with HDGC also have an increased risk of developing a type of breast cancer that begins in the lobules (milk glands) of the breast. HDGC is usually caused by mutations (changes) in the CDH1 gene that are inherited in an autosomal dominant manner. It is a type hereditary cancer syndrome. Also called familial diffuse gastric cancer and hereditary diffuse gastric cancer.
HDR: An amount of radiation that is greater than that given in typical radiation therapy. HDR is precisely directed at the tumor to avoid damaging healthy tissue, and may kill more cancer cells in fewer treatments. Also called high-dose radiation.
HE4: A protein found on cells that line the lungs and reproductive organs, such as the ovaries. HE4 may be found in higher than normal amounts in patients with some types of cancer, including ovarian epithelial cancer. Measuring the amount of HE4 in the blood may help plan cancer treatment or find out if cancer is getting worse or has come back. It is a type of tumor marker. Also called human epididymis protein 4.
head and neck cancer: (... KAN-ser); Cancer that forms in certain areas of the head and neck, including tissues in the nasal cavity (the hollow space inside the nose), sinuses, lips, mouth, salivary glands, throat, and larynx (voice box). Most head and neck cancers begin in squamous cells (thin, flat cells that line the moist surfaces of the head and neck). The most important factors that increase a person’s risk of developing head and neck cancer are tobacco use, heavy alcohol use, and infection with certain types of high-risk human papillomavirus (HPV).
healing touch: (HEEL-ing tuch); A form of complementary and alternative medicine based on the belief that vital energy flows through the human body. This energy is said to be balanced or made stronger by practitioners who pass their hands over, or gently touch, a patient's body. Healing touch is being studied in patients receiving cancer therapy, to find out if it can improve quality of life, boost the immune system, or reduce side effects. Healing touch is a type of energy therapy. Also called therapeutic touch.
health care provider: (helth kayr proh-VY-der); A licensed person or organization that provides health care services. Examples of health care providers include doctors, nurses, therapists, pharmacists, laboratories, hospitals, clinics, and other health care centers.
health care proxy: (helth kayr PRAK-see); A type of advance directive that gives a person (called a proxy) the authority to make medical decisions for another person if that person is not able to make their own decisions. A proxy is usually a spouse, relative, friend, or lawyer who knows the person's values, wishes, and treatment preferences. Also called durable power of attorney for health care and medical power of attorney.
health disparity: (helth dih-SPAYR-ih-tee); A type of preventable health difference that is closely linked with social, political, economic, and environmental disadvantage. Health disparities may occur because of race, ethnicity, sex, gender identity, sexual orientation, age, religion, disability, education, income, where people live, or other characteristics. For example, certain race and ethnic groups may have higher rates of disease, disability, and death than those in other groups because they are more likely to have problems having access to good health care, healthy food, or the latest medical treatments. Research is being done to learn more about health disparities in certain groups of people and ways to reduce them.
health equity: (helth EH-kwih-tee); A situation in which all people are given the chance to live as healthy a life as possible regardless of their race, ethnicity, sex, sexual orientation, disability, education, job, religion, language, where they live, or other factors. A lack of health equity can result in differences in health outcomes, such as rates and severity of disease, disability, death, and quality of life. There are efforts to promote health equity by looking at root causes and removing barriers to equal access to health care services.
health history: (helth HIH-stuh-ree); A record of information about a person’s health. A personal health history may include information about allergies, illnesses, surgeries, immunizations, and results of physical exams and tests. It may also include information about medicines taken and health habits, such as diet and exercise. A family health history includes health information about a person’s close family members (parents, grandparents, children, brothers, and sisters). This includes their current and past illnesses. A family health history may show a pattern of certain diseases in a family. Also called medical history.
Health Insurance Portability and Accountability Act: (helth in-SHOOR-ents por-tuh-BIH-lih-tee ... uh-KOWN-tuh-BIH-lih-tee ...); A 1996 U.S. law that allows workers and their families to keep their health insurance when they change or lose their jobs. The privacy rule of the Health Insurance Portability and Accountability Act protects the privacy of a person’s health information and keeps it from being misused. It gives people the right to receive and review their health records and to choose with whom their health care providers and health insurance companies share their information (including friends, family members, and caregivers). The law also includes standards for setting up and maintaining secure electronic health records. Also called HIPAA and Kassebaum Kennedy Act.
health insurance premium: (helth in-SHOOR-ents PREE-mee-um); The amount of money that a patient pays monthly to a health insurance company for health care coverage. Coverage may include visits to the doctor, laboratory tests, prescription medicines, and hospital stays.
healthy control: (HEL-thee kun-TROLE); In a clinical study, a person who does not have the disorder or disease being studied. Results from healthy controls are compared to results from the group being studied.
heart cancer: (hart KAN-ser); A rare cancer that develops in tissues of the heart. Also called cardiac sarcoma.
heart disease: (hart dih-ZEEZ); A type of disease that affects the heart or blood vessels. The risk of certain heart diseases may be increased by smoking, high blood pressure, high cholesterol, unhealthy diet, lack of exercise, and obesity. The most common heart disease is coronary artery disease (narrow or blocked coronary arteries), which can lead to chest pain, heart attacks, or stroke. Other heart diseases include congestive heart failure, heart rhythm problems, congenital heart disease (heart disease at birth), and endocarditis (inflamed inner layer of the heart). Also called cardiovascular disease.
heart rate: (hart rayt); In medicine, the number of times the heart beats within a certain time period, usually a minute. The heart rate can be felt at the wrist, side of the neck, back of the knees, top of the foot, groin, and other places in the body where an artery is close to the skin. The resting heart rate is normally between 60 and 100 beats a minute in a healthy adult who is at rest. Measuring the heart rate gives important information about a person’s health. Also called pulse.
heat-shock protein: (... PROH-teen); One of a group of proteins that help protect cells from stresses such as heat, cold, and low amounts of oxygen or glucose (sugar). Heat-shock proteins help other proteins function in normal cells and may be present at high levels in cancer cells. Blocking the activity of a heat-shock protein called HSP90 is being studied in the treatment of cancer. Other heat-shock proteins including HSP70 and gp96 are being studied in vaccines to treat cancer. Also called HSP and stress protein.
hedgehog signaling pathway: (HEJ-hog SIG-nuh-ling PATH-way); Describes a group of proteins that work together in a cell to send signals from the cell membrane to the nucleus. The hedgehog signaling pathway is involved in cell growth and differentiation that occurs during the formation of tissues and organs in an embryo. It also plays an important role in the maintenance of stem cells (cells from which other types of cells develop) and in the repair and regeneration of adult tissues. Abnormalities in proteins that are part of the hedgehog signaling pathway may lead to birth defects or diseases such as cancer. Drugs that target this pathway are being used to treat some types of cancer. These drugs may help keep cancer cells from growing.
Hedyotis diffusa: (heh-dee-OH-tis dih-FYOO-suh); An herb used in traditional Chinese medicine to treat certain medical problems. It has been used to boost the immune system and may have anticancer effects.
helical computed tomography: (HEE-lih-kul kum-PYOO-ted toh-MAH-gruh-fee); A procedure that uses a computer linked to an x-ray machine to make a series of detailed pictures of areas inside the body. The x-ray machine scans the body in a spiral path. This allows more images to be made in a shorter time than with older CT methods. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly on the x-ray. Helical computed tomography also creates more detailed pictures and may be better at finding small abnormal areas inside the body. It may be used to help diagnose disease, plan treatment, or find out how well treatment is working. Also called spiral CT scan.
helical tomotherapy: (HEE-lih-kul toh-mah-THAYR-uh-pee); A type of therapy in which radiation is aimed at a tumor from many different directions. The patient lays on a table and is moved through a donut-shaped machine. The radiation source in the machine rotates around the patient in a spiral pattern. Before radiation, a 3-dimensional (3-D) image of the tumor is taken. This helps doctors find the highest dose of radiation that can be used to kill tumor cells while causing less damage to nearby tissue. Helical tomotherapy is a type of intensity-modulated radiation therapy (IMRT). Also called tomotherapy.
Helicobacter pylori: (HEEL-ih-koh-BAK-ter py-LOR-ee); A type of bacterium that causes inflammation and ulcers in the stomach or small intestine. People with Helicobacter pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma. Also called H. pylori.
helper T cell: (HEL-per … sel); A type of immune cell that stimulates killer T cells, macrophages, and B cells to make immune responses. A helper T cell is a type of white blood cell and a type of lymphocyte. Also called CD4-positive T lymphocyte.
hemagglutinin-neuraminidase: (HEE-muh-GLOO-tih-nin-NOOR-uh-MIH-nih-days); A protein found in the outer coat of paramyxoviruses. This protein helps virus particles bind to cells, making infection easier.
Hemangeol: (hee-MAN-jee-ol); A drug that contains the active ingredient propranolol hydrochloride and is used to treat infants 5 weeks to 5 months of age with infantile hemangioma (a benign blood vessel tumor). It is also being studied in the treatment of other conditions and some types of cancer. Hemangeol may help shrink certain types of vascular tumors. It is a type of beta blocker.
hemangiopericytoma: (hee-MAN-jee-oh-PAYR-ih-sy-TOH-muh); A type of cancer involving blood vessels and soft tissue.
hemangiosarcoma: (hee-MAN-jee-oh-sar-KOH-muh); A type of cancer that begins in the cells that line blood vessels.
hematocrit: (hee-MA-toh-krit); The amount of whole blood that is made up of red blood cells. It depends on the number and size of red blood cells. A hematocrit test is usually part of a complete blood count (CBC). It may be used to check for conditions such as anemia, dehydration, malnutrition, and leukemia. Also called HCT.
hematogenous: (HEE-muh-TAH-jeh-nus); Originating in the blood or spread through the bloodstream.
hematologic cancer: (HEE-muh-tuh-LAH-jik KAN-ser); Cancer that begins in blood-forming tissue, such as the bone marrow, or in the cells of the immune system. Examples of hematologic cancer are leukemia, lymphoma, and multiple myeloma. Also called blood cancer.
hematologist: (HEE-muh-TAH-loh-jist); A doctor who has special training in diagnosing and treating blood disorders.
hematoma: (HEE-muh-TOH-muh); A pool of mostly clotted blood that forms in an organ, tissue, or body space. A hematoma is usually caused by a broken blood vessel that was damaged by surgery or an injury. It can occur anywhere in the body, including the brain. Most hematomas are small and go away on their own, but some may need to be removed by surgery.
hematopathology laboratory: (hee-MA-toh-pa-THAH-loh-jee LA-bruh-tor-ee); A laboratory that specializes in doing tests that help to diagnose and treat diseases of the blood, bone marrow, and lymph system.
hematopoiesis: (hee-MA-toh-poy-EE-sis); The formation of new blood cells.
hematopoietic growth factor: (hee-MA-toh-poy-EH-tik ...); A group of proteins that causes blood cells to grow and mature.
hematopoietic stem cell: (hee-MA-toh-poy-EH-tik stem sel); An immature cell that can develop into all types of blood cells, including white blood cells, red blood cells, and platelets. Hematopoietic stem cells are found in the peripheral blood and the bone marrow. Also called blood stem cell.
hematopoietic tissue: (hee-MA-toh-poy-EH-tik TIH-shoo); Tissue in which new blood cells are formed.
hematoporphyrin derivative: (HEE-muh-toh-POR-fih-rin deh-RIH-vuh-tiv); A drug used in photodynamic therapy that is absorbed by tumor cells. When exposed to light, it becomes active and kills the cancer cells.
hematoxylin and eosin staining: (hee-muh-TOK-suh-lin … EE-oh-sin STAY-ning); A common laboratory method that uses two dyes called hematoxylin and eosin that make it easier to see different parts of the cell under a microscope. Hematoxylin shows the ribosomes, chromatin (genetic material) within the nucleus, and other structures as a deep blue-purple color. Eosin shows the cytoplasm, collagen, connective tissue, and other structures that surround and support the cell as an orange-pink-red color. Hematoxylin and eosin staining helps identify different types of cells and tissues and provides important information about the pattern, shape, and structure of cells in a tissue sample. It is used to help diagnose diseases, such as cancer. Also called H and E staining.
hematuria: (HEE-muh-TOOR-ee-uh); Blood in the urine.
heme: (heem); The part of certain molecules that contains iron. The heme part of hemoglobin is the substance inside red blood cells that binds to oxygen in the lungs and carries it to the tissues.
hemihyperplasia: (HEH-mee-HY-per-PLAY-zhuh); A condition in which one side of the body or a part of one side is larger than the other. Children with hemihyperplasia have an increased risk of developing certain types of cancer, including Wilms tumor (a childhood kidney cancer) and liver cancer. Also called hemihypertrophy.
hemihypertrophy: (HEH-mee-hy-PER-troh-fee); A condition in which one side of the body or a part of one side is larger than the other. Children with hemihypertrophy have an increased risk of developing certain types of cancer, including Wilms tumor (a childhood kidney cancer) and liver cancer. Also called hemihyperplasia.
hemilaryngectomy: (HEM-ee-LAYR-in-JEK-toh-mee); An operation to remove one side of the larynx (voicebox).
hemizygous: (HEH-mee-ZY-gus); A term that describes a person who has only one copy of a gene rather than the usual two copies. Hemizygosity can occur under normal conditions. For example, because most males have one X chromosome and one Y chromosome, they are hemizygous for genes on those chromosomes. Hemizygosity can also occur under abnormal conditions, such as when two copies of a gene should be present but one is missing. For example, Turner syndrome occurs when a female inherits only one copy of the X chromosome instead of the usual two copies.
hemochromatosis: (HEE-moh-kroh-muh-TOH-sis); A condition in which the body takes up and stores more iron than it needs. The extra iron is stored in the liver, heart, and pancreas, which may cause liver disease, heart problems, organ failure, and cancer. It may also cause bronze skin, diabetes, pain in the joints and abdomen, tiredness, and impotence. Hemochromatosis may be inherited, or it may be caused by blood transfusions. Also called iron overload.
hemoglobin: (HEE-moh-GLOH-bin); A protein inside red blood cells that carries oxygen from the lungs to tissues and organs in the body and carries carbon dioxide back to the lungs. Testing for the amount of hemoglobin in the blood is usually part of a complete blood cell (CBC) test.
hemolysis: (hee-MAH-lih-sis); The breakdown of red blood cells. Some diseases, medicines, and toxins may cause red blood cells to break down more quickly than usual.
hemophagocytic lymphohistiocytosis: (HEE-moh-FA-goh-SIH-tik LIM-foh-HIS-tee-oh-sy-TOH-sis); A rare disorder in which histiocytes and lymphocytes (types of white blood cells) build up in organs including the skin, spleen, and liver, and destroy other blood cells. Hemophagocytic lymphohistiocytosis may be inherited or caused by certain conditions or diseases, including infections, immunodeficiency (inability of the body to fight infections), and cancer. Also called HLH.
hemophilia: (HEE-moh-FIH-lee-uh); Group of hereditary disorders in which affected individuals fail to make enough of certain proteins needed to form blood clots.
hemoptysis: (hee-MOP-tih-sis); Coughing or spitting up blood from the respiratory tract.
hemorrhage: (HEH-muh-rij); In medicine, loss of blood from damaged blood vessels. A hemorrhage may be internal or external, and usually involves a lot of bleeding in a short time.
hemorrhagic cerebrovascular accident: (HEH-muh-RA-jik seh-REE-broh-VAS-kyoo-ler AK-sih-dent); A type of stroke that occurs when a blood vessel in the brain or on the surface of the brain leaks or breaks open, causing bleeding in or around the brain. This leads to swelling and pressure, which can damage cells and tissue in the brain. Hemorrhagic cerebrovascular accident is usually caused by high blood pressure, aneurysm, arteriovenous malformation, head injury, or a bleeding disorder. Also called hemorrhagic stroke.
hemorrhagic cystitis: (HEH-muh-RA-jik sis-TY-tis); A condition in which the lining of the bladder becomes inflamed and starts to bleed. The blood can be seen in the urine. Symptoms include pain and a burning feeling while urinating, feeling a need to urinate often, and being unable to control the flow of urine. Hemorrhagic cystitis may be caused by anticancer drugs, radiation therapy, infection, or being exposed to chemicals, such as dyes or insecticides.
hemorrhagic stroke: (HEH-muh-RA-jik stroke); A type of stroke that occurs when a blood vessel in the brain or on the surface of the brain leaks or breaks open, causing bleeding in or around the brain. This leads to swelling and pressure, which can damage cells and tissue in the brain. Hemorrhagic stroke is usually caused by high blood pressure, aneurysm, arteriovenous malformation, head injury, or a bleeding disorder. Also called hemorrhagic cerebrovascular accident.
hemorrhoid: (HEH-muh-ROYD); An enlarged or swollen blood vessel, usually located near the anus or the rectum.
hemp: An herb that comes from a variant of the Cannabis sativa plant and contains fiber, seeds, and oil used to make many different industrial and consumer products. These include textiles, building materials, paper, fabrics, soap, food, dietary supplements, and cosmetics. Hemp and marijuana come from the same species of Cannabis sativa, but the hemp variant contains very low levels of delta-9-THC (the main active chemical in marijuana that causes drug-like effects in the body). The hemp and marijuana variants of Cannabis sativa have their own chemical and genetic makeup and are regulated, grown, and used in different ways. Also called industrial hemp.
heparin: (HEH-puh-rin); A substance that slows the formation of blood clots. Heparin is made by the liver, lungs, and other tissues in the body and can also made in the laboratory. Heparin may be injected into muscle or blood to prevent or break up blood clots. It is a type of anticoagulant.
hepatectomy: (HEH-puh-TEK-toh-mee); Surgery to remove all or part of the liver.
hepatic: (heh-PA-tik); Refers to the liver.
hepatic arterial infusion: (heh-PA-tik ar-TEER-ee-ul in-FYOO-zhun); A procedure to deliver chemotherapy directly to the liver. Catheters are put into an artery in the groin that leads directly to the liver, and drugs are given through the catheters.
hepatic arterial occlusion: (heh-PA-tik ar-TEER-ee-ul uh-KLOO-zhun); A block in blood flow to the liver. It can happen while giving chemotherapy through a catheter in the hepatic artery. Sometimes doctors use drugs or other agents to cause hepatic arterial occlusion on purpose. This block of blood flow to the liver helps kill cancer cells growing in the liver.
hepatic artery: (heh-PA-tik AR-tuh-ree); The major blood vessel that carries blood to the liver.
hepatic portal vein: (heh-PA-tik POR-tul vayn); A blood vessel that carries blood to the liver from the intestines, spleen, pancreas, and gallbladder. Also called portal vein.
hepatic veno-occlusive disease: (heh-PA-tik VEE-noh-uh-KLOO-siv dih-ZEEZ); A condition in which some of the veins in the liver are blocked. This causes a decrease in blood flow inside the liver and may lead to liver damage. Signs and symptoms include weight gain, yellowing of the skin and whites of the eyes, dark-colored urine, and increased liver size. It may occur at some point in time after radiation therapy to the liver and bile ducts or after high-dose anticancer drugs were given before a stem cell transplant. Also called sinusoidal obstruction syndrome.
hepatitis: (HEH-puh-TY-tis); Disease of the liver causing inflammation. Symptoms include an enlarged liver, fever, nausea, vomiting, abdominal pain, and dark urine.
hepatitis A vaccine: (HEH-puh-TY-tis ... vak-SEEN); A vaccine used to prevent infection with the hepatitis A virus, which causes a serious liver disease. The vaccine is made of a weakened form of the virus that cannot cause disease but causes the body’s immune system to make antibodies that destroy the hepatitis A virus.
hepatitis A virus: (HEH-puh-TY-tis ... VY-rus); A virus that causes a serious liver disease. It is usually spread by contact with an infected person’s stool by eating food he or she has handled after not washing hands, but it can be spread in other ways. Symptoms of infection include jaundice, dark urine, and fever and other flu-like symptoms.
hepatitis B virus: (HEH-puh-TY-tis ... VY-rus); A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although many patients who are infected with hepatitis B virus may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. Also called HBV.
hepatitis C virus: (HEH-puh-TY-tis ... VY-rus); A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although patients who are infected with hepatitis C virus may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. These patients may also have an increased risk for certain types of non-Hodgkin lymphoma. Also called HCV.
hepatitis D virus: (HEH-puh-TY-tis … VY-rus); A type of hepatitis virus that may be present in the body at the same time as the hepatitis B virus. It makes the hepatitis (inflammation of the liver) caused by hepatitis B much worse. The hepatitis D virus and the hepatitis B virus are spread to others through blood or sexual contact. Infants born to infected mothers may also become infected with the virus. Also called hepatitis delta virus.
hepatitis delta virus: (HEH-puh-TY-tis DEL-tuh VY-rus); A type of hepatitis virus that may be present in the body at the same time as the hepatitis B virus. It makes the hepatitis (inflammation of the liver) caused by hepatitis B much worse. The hepatitis delta virus and the hepatitis B virus are spread to others through blood or sexual contact. Infants born to infected mothers may also become infected with the virus. Also called hepatitis D virus.
hepatitis E virus: (HEH-puh-TY-tis … VY-rus); A virus that causes hepatitis (inflammation of the liver). It is usually spread through food that has been handled by an infected person, or through drinking water that is contaminated with human waste.
hepatitis G virus: (HEH-puh-TY-tis … VY-rus); A virus that may be found in patients with hepatitis (inflammation of the liver). It is spread to others through blood or sexual contact. Infants born to infected mothers may also become infected with the virus.
hepatobiliary: (heh-PA-toh-BIH-lee-AYR-ee); Having to do with the liver, bile ducts, and/or gallbladder.
hepatoblastoma: (HEH-puh-toh-bla-STOH-muh); A type of liver tumor that occurs in infants and children.
hepatocellular carcinoma: (heh-PA-toh-SEL-yoo-ler KAR-sih-NOH-muh); A type of cancer that forms in liver cells called hepatocytes. Hepatocytes are the most common cells of the liver, and they carry out most of the functions of the liver.  Factors that may increase a person’s risk of developing hepatocellular carcinoma include having chronic infection with hepatitis B virus or hepatitis C virus, non-alcoholic steatohepatitis, chronic alcohol use disorder, and cirrhosis. Most adult primary liver cancers are hepatocellular carcinomas. Also called HCC.
hepatocyte: (heh-PA-toh-site); A liver cell.
hepatolenticular degeneration: (heh-PA-toh-len-TIH-kyoo-ler dee-JEH-neh-RAY-shun); A rare, inherited disorder in which too much copper builds up in the body. The extra copper is stored in the body’s tissues and organs, especially in the liver, brain, and eyes. This can cause liver disease, central nervous system (brain and spinal cord) problems, and mental problems. Signs and symptoms of hepatolenticular degeneration include yellowing of the skin and the whites of the eyes, a gold or brown ring around the colored part of the eyes, swelling in the abdomen and legs, fatigue, loss of appetite, problems with speech and swallowing, uncontrolled movements or muscle stiffness, anxiety, depression, and mood swings. Hepatolenticular degeneration is caused by mutations (changes) in the ATP7B gene. It is a genetic disorder that is inherited in an autosomal recessive manner and is usually diagnosed in teens and young adults. It is a type of copper storage disease. Also called Wilson disease.
hepatoma: (HEH-puh-TOH-muh); A liver tumor.
hepatomegaly: (HEH-puh-toh-MEH-guh-lee); Enlarged liver.
Hepzato: (hep-ZA-toh); A drug that contains the active ingredient melphalan hydrochloride and is used to treat adults with uveal melanoma (a type of eye cancer) that has spread to less than half of the liver and cannot be removed by surgery. Hepzato is given as an infusion directly into an artery that leads to the liver. It may kill cancer cells by damaging their DNA and stopping them from dividing. Hepzato is a type of alkylating agent.
HER1: A protein found on certain types of cells that binds to a substance called epidermal growth factor. The HER1 protein is involved in cell signaling pathways that control cell division and survival. Sometimes, mutations (changes) in the EGFR gene cause HER1 proteins to be made in higher than normal amounts on some types of cancer cells. This causes cancer cells to divide more rapidly. Drugs that block HER1 proteins are being used in the treatment of some types of cancer. HER1s are a type of receptor tyrosine kinase. Also called EGFR, epidermal growth factor receptor, and ErbB1.
HER1 gene: A gene that makes a protein that is involved in cell growth and cell survival. Mutated (changed) forms of the HER1 gene and protein have been found in some types of cancer, including non-small cell lung cancer. These changes may cause cancer cells to grow and spread in the body. Checking for changes in the HER1 gene in tumor tissue may help plan cancer treatment. Also called EGFR gene, epidermal growth factor receptor gene, and ERBB1 gene.
HER2: A protein involved in normal cell growth. HER2 may be made in larger than normal amounts by some types of cancer cells, including breast, ovarian, bladder, pancreatic, stomach, and esophageal cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. Checking the amount of HER2 on some types of cancer cells may help plan treatment. Also called c-erbB-2, HER2/neu, human EGF receptor 2, and human epidermal growth factor receptor 2.
HER2 negative: (… NEH-guh-tiv); Describes cells that have a small amount or none of a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. Cancer cells that are HER2 negative may grow more slowly and are less likely to recur (come back) or spread to other parts of the body than cancer cells that have a large amount of HER2 on their surface. Checking to see if a cancer is HER2 negative may help plan treatment. Cancers that may be HER2 negative include breast, bladder, ovarian, pancreatic, and stomach cancers. Also called human epidermal growth factor receptor 2 negative.
HER2 positive: (… PAH-zih-tiv); Describes cells that have a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. Cancer cells that make too much HER2 may grow more quickly and are more likely to spread to other parts of the body. Checking to see if a cancer is HER2 positive may help plan treatment, which may include drugs that kill HER2-positive cancer cells. Cancers that may be HER2 positive include breast, bladder, pancreatic, ovarian, and stomach cancers. Also called c-erbB-2 positive and human epidermal growth factor receptor 2 positive.
HER2 test: A laboratory test that measures the amount of HER2 protein on cancer cells or how many copies of the HER2 gene are in the DNA of cancer cells. The HER2 protein helps control normal cell growth. Larger than normal amounts of the HER2 protein or too many copies of the HER2 gene may be made by some types of cancer, including breast, ovarian, bladder, pancreatic, and stomach cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. A HER2 test may be done to help plan treatment, which may include drugs that target the HER2 protein. It is a type of tumor marker test. Also called HER2/neu test and human epidermal growth factor receptor 2 test.
HER2-low breast cancer: (… brest KAN-ser); A type of breast cancer in which the cancer cells have a small amount of a protein called HER2 on their surface and do not have more than two copies of the HER2 gene. HER2-low breast cancer has usually been treated like HER2-negative breast cancer because the cancer cells do not make enough HER2 protein for drugs that target HER2 to work. However, newer drugs that target HER2 have been shown to be effective in treating HER2-low breast cancer.
HER2/neu: A protein involved in normal cell growth. HER2/neu may be made in larger than normal amounts by some types of cancer cells, including breast, ovarian, bladder, pancreatic, stomach, and esophageal cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. Checking the amount of HER2/neu on some types of cancer cells may help plan treatment. Also called c-erbB-2, HER2, human EGF receptor 2, and human epidermal growth factor receptor 2.
HER2/neu test: A laboratory test that measures the amount of HER2/neu protein on cancer cells or how many copies of the HER2/neu gene are in the DNA of cancer cells. The HER2/neu protein helps control normal cell growth. Larger than normal amounts of the HER2/neu protein or too many copies of the HER2/neu gene may be made by some types of cancer, including breast, ovarian, bladder, pancreatic, and stomach cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. A HER2/neu test may be done to help plan treatment, which may include drugs that target the HER2/neu protein. It is a type of tumor marker test. Also called HER2 test and human epidermal growth factor receptor 2 test.
herba Scutellaria barbatae: (ER-buh skoo-teh-LAYR-ee-uh BAR-buh-tay); An herb used in traditional Chinese medicine to treat certain medical problems. It may have anticancer effects.
herbal: (ER-bul); Having to do with plants.
herbal cigarette: (ER-bul SIH-guh-ret); A type of cigarette that contains a mixture of flowers, herbs, and other natural ingredients. Herbal cigarettes do not contain tobacco or nicotine. When they are smoked, they make many of the same harmful chemicals found in tobacco smoke, including tar and carbon monoxide.
herbal medicine: (ER-bul MEH-dih-sin); A type of medicine that uses roots, stems, leaves, flowers, or seeds of plants to improve health, prevent disease, and treat illness.
herbal supplement: (ER-bul SUH-pleh-ment); A product made from a plant that is thought to be useful in treating disease or staying healthy. Herbal supplements are taken by mouth.
herbicide: (ER-bih-side); A chemical that kills plants.
Herceptin: (her-SEP-tin); A drug used alone or with other drugs to treat certain types of breast cancer, stomach cancer, and gastroesophageal junction cancer that are HER2 positive. It is also being studied in the treatment of other types of cancer. Herceptin binds to a protein called HER2, which is found on some cancer cells. This may help the immune system kill cancer cells. Herceptin is a type of monoclonal antibody and a type of HER2 receptor antagonist. Also called Hercessi, Herzuma, Kanjinti, Ogivri, Ontruzant, trastuzumab, and Trazimera.
Herceptin Hylecta: (her-SEP-tin hy-LEK-tuh); A combination of trastuzumab and hyaluronidase used alone or with other drugs to treat adults with certain types of HER2-positive breast cancer. Trastuzumab binds to a protein called HER2, which is found on some cancer cells. This may help the immune system kill cancer cells. Hyaluronidase allows trastuzumab to be given by injection under the skin. Herceptin Hylecta can be given in less time than trastuzumab alone, which is given as an infusion. Also called trastuzumab and hyaluronidase.
Hercessi: (her-SEH-see); A drug used alone or with other drugs to treat certain types of breast cancer, stomach cancer, and gastroesophageal junction cancer that are HER2 positive. It is also being studied in the treatment of other types of cancer. Hercessi binds to a protein called HER2, which is found on some cancer cells. This may help the immune system kill cancer cells. Hercessi is a type of monoclonal antibody and a type of HER2 receptor antagonist. Also called Herceptin, Herzuma, Kanjinti, Ogivri, Ontruzant, trastuzumab, and Trazimera.
herd immunity: (… ih-MYOO-nih-tee); Protection from an infectious disease as a result of living in a community where a large number of people are vaccinated against that disease. When enough people are vaccinated against a disease, it is harder for the disease to spread. Herd immunity helps protect those who have not been vaccinated, including newborns, pregnant women, and people with certain illnesses who cannot receive vaccines. Also called community immunity.
hereditary: (heh-REH-dih-tayr-ee); In medicine, describes the passing of genetic information from parent to child through the genes in sperm and egg cells. Also called inherited.
hereditary breast and ovarian cancer syndrome: (heh-REH-dih-tayr-ee brest … oh-VAYR-ee-un KAN-ser SIN-drome); An inherited disorder in which the risk of breast cancer (especially before the age of 50) and ovarian cancer is higher than normal. Most cases of hereditary breast and ovarian cancer syndrome are caused by certain mutations (changes) in the BRCA1 or the BRCA2 gene. People with hereditary breast and ovarian cancer syndrome may also have an increased risk of other types of cancer, including pancreatic cancer, prostate cancer, and melanoma. Also called HBOC syndrome.
hereditary cancer syndrome: (heh-REH-dih-tayr-ee KAN-ser SIN-drome); A type of inherited disorder in which there is a higher-than-normal risk of certain types of cancer. Hereditary cancer syndromes are caused by mutations (changes) in certain genes passed from parents to children. In a hereditary cancer syndrome, certain patterns of cancer may be seen within families. These patterns include having several close family members (such as a mother, daughter, and sister) with the same type of cancer, developing cancer at an early age, or having two or more types of cancer develop in the same person. Examples of hereditary cancer syndromes are hereditary breast and ovarian cancer syndrome, Li-Fraumeni syndrome, Cowden syndrome, and Lynch syndrome. Also called family cancer syndrome and inherited cancer syndrome.
hereditary diffuse gastric cancer: (heh-REH-dih-tayr-ee dih-FYOOS GAS-trik KAN-ser); A rare, inherited disorder that increases the risk of developing a type of stomach cancer called diffuse gastric cancer. This cancer grows in the lining of the stomach, which causes the lining to become thick and hard. The cancer is also likely to spread to other parts of the body, such as the liver or bone. Women with hereditary diffuse gastric cancer also have an increased risk of developing a type of breast cancer that begins in the lobules (milk glands) of the breast. Hereditary diffuse gastric cancer is usually caused by mutations (changes) in the CDH1 gene that are inherited in an autosomal dominant manner. It is a type hereditary cancer syndrome. Also called familial diffuse gastric cancer and HDGC.
hereditary hemochromatosis: (heh-REH-dih-tayr-ee HEE-moh-kroh-muh-TOH-sis); An inherited condition in which too much iron builds up in the body. The extra iron is stored in the body’s tissues and organs, especially the liver, heart, pancreas, skin, and joints. This can cause liver disease, heart problems, diabetes, and organ failure. Symptoms include changes in skin color, pain in the joints and abdomen, fatigue, and loss of sex drive. Patients with hereditary hemochromatosis also have an increased risk of liver cancer. There are five types of hereditary hemochromatosis. Each type is caused by changes in different genes. Symptoms for each type typically begin at different ages. Type 1 hemochromatosis is one of the most common genetic disorders in the United States.
hereditary leiomyomatosis and renal cell cancer: (heh-REH-dih-tayr-ee LY-oh-MY-oh-muh-TOH-sis ... REE-nul sel KAN-ser); A rare, inherited disorder in which benign (not cancer) skin lesions called leiomyomas form in the smooth muscle tissue around the hair follicles. They usually form on the arms, legs, chest, and abdomen. Benign leiomyomas may also form as fibroids in the uterus in females. People with hereditary leiomyomatosis and renal cell cancer have an increased risk of kidney cancer. The signs and symptoms of hereditary leiomyomatosis and renal cell cancer usually do not appear until young adulthood. Hereditary leiomyomatosis and renal cell cancer is caused by a mutation in the FH gene. It is inherited in an autosomal dominant manner. Also called HLRCC.
hereditary nonpolyposis colorectal cancer: (heh-REH-dih-tayr-ee non-PAH-lee-POH-sis KOH-loh-REK-tul KAN-ser); An inherited disorder that increases the risk of developing colorectal cancer, endometrial cancer, ovarian cancer, and many other types of cancer, such as cancers of the stomach, small intestine, pancreas, bile duct, urinary tract, and brain, often before age 50. Hereditary nonpolyposis colorectal cancer is caused by mutations (changes) in genes that affect DNA mismatch repair, a process that fixes mistakes that occur when DNA is copied. These genes are MLH1, MSH2, MSH6, PMS2, and EPCAM. Also called HNPCC and Lynch syndrome.
hereditary papillary renal cancer: (heh-REH-dih-tayr-ee PA-pih-LAYR-ee REE-nul KAN-ser); A rare, inherited disorder that increases the risk of a type of kidney cancer called type 1 papillary kidney cancer. This cancer forms in cells that line the small tubes in the kidney that filter waste from the blood and make urine. Hereditary papillary renal cancer often affects both kidneys, and often there is more than one tumor in each kidney. It is caused by mutations (changes) in a gene called MET. Hereditary papillary renal cancer is a type of hereditary cancer syndrome. Also called hereditary papillary renal carcinoma and HPRC.
hereditary papillary renal carcinoma: (heh-REH-dih-tayr-ee PA-pih-LAYR-ee REE-nul KAR-sih-NOH-muh); A rare, inherited disorder that increases the risk of a type of kidney cancer called type 1 papillary kidney cancer. This cancer forms in cells that line the small tubes in the kidney that filter waste from the blood and make urine. Hereditary papillary renal carcinoma often affects both kidneys, and often there is more than one tumor in each kidney. It is caused by mutations (changes) in a gene called MET. Hereditary papillary renal carcinoma is a type of hereditary cancer syndrome. Also called hereditary papillary renal cancer and HPRC.
hereditary paraganglioma-pheochromocytoma syndrome: (heh-REH-dih-tayr-ee PAYR-uh-GANG-glee-OH-muh-FEE-oh-KROH-moh-sy-TOH-muh SIN-drome); A rare, genetic disorder marked by tumors called paragangliomas, which are found in paraganglia. Paraganglia are groups of nerve-like cells found near the adrenal glands and near blood vessels or nerves in the head, neck, chest, abdomen, and pelvis. Paragangliomas that form in the adrenal glands are called pheochromocytomas. Paragangliomas are usually benign (not cancer), but sometimes become malignant (cancerous). People with hereditary paraganglioma-pheochromocytoma syndrome usually have more than one paraganglioma, and may have an increased risk of certain types of cancer, such as kidney cancer and thyroid cancer.
hereditary predisposition: (heh-REH-dih-tayr-ee PREE-dih-spuh-ZIH-shun); An inherited increase in the risk of developing a disease. Also called genetic predisposition, genetic susceptibility, and inherited predisposition.
hereditary syndrome: (heh-REH-dih-tayr-ee SIN-drome); A disorder caused by mutations (changes) in certain genes or chromosomes that are passed down from parent to child. Hereditary syndromes may be inherited from one or both parents, and several close family members (such as a mother, daughter, and sister) may have the same disorder. There are many different types of hereditary syndromes, including those in which family members have a higher-than-normal risk of developing certain types of cancer.
heritable: (HAYR-ih-tuh-bul); In medicine, describes a characteristic or trait that can be passed from a parent to a child through the genes. Several types of cancer have heritable forms, in which the risk of developing a particular type of cancer is inherited from a parent. Some signs of heritable cancer are a family history of the cancer, mutations (changes) in certain genes passed from a parent to a child, or a mutation that occurs at the time of conception (fertilization of an egg by a sperm). Heritable forms of cancer often develop at an early age.
heritage: (HAYR-ih-tij); Something handed down from the past, such as a tradition, birthright, or inherited traits.
hernia: (HER-nee-uh); The bulging of an internal organ through a weak area or tear in the muscle or other tissue that holds it in place. Most hernias occur in the abdomen.
heroin: (HAYR-oh-win); A highly addictive substance once used to treat severe pain but is now illegal to use or sell in the United States. It is made from morphine, a natural substance found in the seed pods of the opium poppy plant. Heroin works by binding to mu opioid receptors in the central nervous system, which blocks pain signals and changes how the body responds to pain. It is a type of analgesic (pain reliever) and a type of opiate. Also called diacetylmorphine and diamorphine.
herpes simplex virus: (HER-peez SIM-plex VY-rus); A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of herpes simplex viruses. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called HHV, HSV, and human herpesvirus.
herpes zoster: (HER-peez ZOS-ter); A common condition that occurs when the virus that causes chickenpox is reactivated in the body. After having chickenpox, the virus stays inactive in the body, usually in the nerves along the spinal cord or at the base of the skull. The virus can become active again many years later and cause herpes zoster. Herpes zoster is marked by a painful rash that usually appears as small clusters of blisters. The blisters often form a band across the skin on one side of the body, especially on the chest, back, waist, or face. The pain in the affected area can last for many weeks or months after the rash disappears. Other symptoms may include fever, chills, headache, fatigue, and upset stomach. Herpes zoster is most common in older adults and in those who have a weakened immune system. It cannot be passed from person to person, but those who have never had chickenpox or the chickenpox vaccine can develop chickenpox if they come in contact with a person who has herpes zoster. Vaccines are available to prevent herpes zoster. Also called shingles.
herpesvirus: (HER-peez-VY-rus); A member of the herpes family of viruses.
Herzuma: (her-ZOO-muh); A drug used alone or with other drugs to treat certain types of breast cancer, stomach cancer, and gastroesophageal junction cancer that are HER2 positive. It is also being studied in the treatment of other types of cancer. Herzuma binds to a protein called HER2, which is found on some cancer cells. This may help the immune system kill cancer cells. Herzuma is a type of monoclonal antibody and a type of HER2 receptor antagonist. Also called Herceptin, Hercessi, Kanjinti, Ogivri, Ontruzant, trastuzumab, and Trazimera.
heterocyclic amine: (HEH-teh-roh-SY-klik A-meen); A chemical that is formed when meat, poultry, or fish is cooked at high temperatures, such as frying, broiling, and barbecuing. Heterocyclic amines are carcinogens (substances that may cause cancer). Also called HCA.
heterogeneous: (HEH-teh-roh-JEE-nee-us); Made up of elements or ingredients that are not alike.
heterogeneously dense breast tissue: (HEH-teh-roh-JEE-nee-us-lee dents brest TIH-shoo); A term used to describe breast tissue that has large areas of dense fibrous tissue and glandular tissue and also has some fatty tissue. The dense areas of the breast make it harder to find tumors or other changes on a mammogram. Heterogeneously dense breast tissue is one of four categories used to describe a level of breast density seen on a mammogram. About 40% of women have this type of breast tissue.
heterogenic: (HEH-teh-roh-JEH-nik); Derived from a different source or species. Also called heterogenous.
heterogenous: (HEH-teh-RAH-jeh-nus); Derived from a different source or species. Also called heterogenic.
heterozygous genotype: (HEH-teh-roh-ZY-gus JEE-noh-tipe); A term that describes having two different versions of the same gene (one inherited from the mother and one inherited from the father). In a heterozygous genotype, each gene may have a different mutation (change) or one of the genes may be mutated and the other one is normal. For example, familial hypercholesterolemia (very high levels of cholesterol in the blood) can occur when a person is heterozygous for the LDLR gene, inheriting a mutated gene from one parent and a normal gene from the other parent.
hexyl 5-aminolevulinate: (HEK-sul 5-uh-MEE-noh-LEH-vyoo-LIH-nayt); A substance that is used to find and kill tumor cells. It enters tumor cells and becomes activated when exposed to a special type of light. A chemical reaction causes the cells to produce fluorescent light and die.
HGS-ETR1: A substance being studied in the treatment of some types of cancer. It binds to a protein called TRAIL R1 on the surface of some tumor cells. This may kill the tumor cells. HGS-ETR1 is a type of monoclonal antibody. Also called anti-TRAIL R1-mAb and mapatumumab.
HGS-ETR2: A substance being studied in the treatment of some types of cancer. It binds to a protein called TRAIL-R2 on the surface of some tumor cells, which may kill the tumor cells. HGS-ETR2 is a type of monoclonal antibody. Also called anti-TRAIL R2 mAb HGS-ETR2 and lexatumumab.
HHS: The U.S. federal government agency responsible for protecting the public’s health and providing important services, especially for people in need. The HHS works with state and local governments throughout the country to do research and provide public health services, food and drug safety programs, health insurance programs, and many other services. There are several federal agencies that are a part of the HHS. They include the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and the Centers for Medicare and Medicaid Services (CMMS). Also called Department of Health and Human Services and DHHS.
HHV: A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of HHVs. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called herpes simplex virus, HSV, and human herpesvirus.
HHV8: A type of virus that causes Kaposi sarcoma (a rare cancer in which lesions grow in the skin, lymph nodes, lining of the mouth, nose, and throat, and other tissues of the body). HHV8 also causes certain types of lymphoma (cancer that begins in cells of the immune system). Also called human herpesvirus 8, Kaposi sarcoma-associated herpesvirus, and KSHV.
HIF: One of a group of proteins that play an important role in how cells respond to changing levels of oxygen. When oxygen levels in cells are low, HIFs activate certain genes involved in cell growth and survival. This allows the cells to function and survive even in low oxygen conditions. HIFs may be made in larger than normal amounts by some types of cancer cells. This may cause cancer cells to grow and spread to other parts of the body. Also called hypoxia-inducible factor.
HIFU: A procedure in which high-energy sound waves are aimed directly at an area of abnormal cells or tissue in the body. The waves create heat that kills the cells. HIFU is being studied in the treatment of prostate cancer and some other types of cancer and other diseases. Also called high-intensity focused ultrasound therapy.
high blood pressure: (hy blud PREH-sher); A blood pressure of 140/90 or higher. High blood pressure usually has no symptoms. It can harm the arteries and cause an increase in the risk of stroke, heart attack, kidney failure, and blindness. Also called hypertension.
high blood sugar: (hy blud SHUH-ger); Higher than normal amount of glucose (a type of sugar) in the blood. High blood sugar can be a sign of diabetes or other conditions. Also called hyperglycemia.
high grade: (hy grayd); A term used to describe cells and tissue that look abnormal under a microscope. High-grade cancer cells tend to grow and spread more quickly than low-grade cancer cells. Cancer grade may be used to help plan treatment and determine prognosis. High-grade cancers usually have a worse prognosis than low-grade cancers and may need treatment right away or treatment that is more aggressive (intensive).
high-dose chemotherapy: (hy-dose kee-moh-THAYR-uh-pee); An intensive drug treatment to kill cancer cells, but that also destroys the bone marrow and can cause other severe side effects. High-dose chemotherapy is usually followed by bone marrow or stem cell transplantation to rebuild the bone marrow.
high-dose radiation: (hy-dose RAY-dee-AY-shun); An amount of radiation that is greater than that given in typical radiation therapy. High-dose radiation is precisely directed at the tumor to avoid damaging healthy tissue, and may kill more cancer cells in fewer treatments. Also called HDR.
high-dose-rate remote brachytherapy: (hy-dose-rayt ree-MOTE BRAY-kee-THAYR-uh-pee); A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote radiation therapy and remote brachytherapy.
high-dose-rate remote radiation therapy: (hy-dose-rayt ree-MOTE RAY-dee-AY-shun THAYR-uh-pee); A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote brachytherapy and remote brachytherapy.
high-energy photon therapy: (hy-EH-ner-jee FOH-ton THAYR-uh-pee); A type of radiation therapy that uses high-energy photons (units of light energy). High-energy photons penetrate deeply into tissues to reach tumors while giving less radiation to superficial tissues such as the skin.
high-grade DCIS: (hy-grayd …); A condition in which cells that look very different from normal cells under a microscope are found in the lining of a breast duct. There may also be areas of dead cells in the abnormal tissue. The abnormal cells have not spread outside the duct to other tissues in the breast. High-grade DCIS tends to grow more quickly than low-grade or intermediate-grade DCIS and is more likely to come back or become invasive breast cancer and spread to other tissues. Also called grade III DCIS, grade III ductal carcinoma in situ, and high-grade ductal carcinoma in situ.
high-grade ductal carcinoma in situ: (hy-grayd DUK-tul KAR-sih-NOH-muh in SY-too); A condition in which cells that look very different from normal cells under a microscope are found in the lining of a breast duct. There may also be areas of dead cells in the abnormal tissue. The abnormal cells have not spread outside the duct to other tissues in the breast. High-grade ductal carcinoma in situ tends to grow more quickly than low-grade or intermediate-grade ductal carcinoma in situ and is more likely to come back or become invasive breast cancer and spread to other tissues. Also called grade III DCIS, grade III ductal carcinoma in situ, and high-grade DCIS.
high-grade lymphoma: (... lim-FOH-muh); A type of lymphoma that grows and spreads quickly and has severe symptoms. Also called aggressive lymphoma and intermediate-grade lymphoma.
high-grade squamous intraepithelial lesion: (... SKWAY-mus IN-truh-eh-pih-THEE-lee-ul LEE-zhun); An area of abnormal cells that forms on the surface of certain organs, such as the cervix, vagina, vulva, anus, and esophagus. High-grade squamous intraepithelial lesions look somewhat to very abnormal when looked at under a microscope. They are usually caused by chronic infection with certain types of human papillomavirus (HPV) and are found when a Pap test or biopsy is done. If not treated, these abnormal cells may become cancer and spread into nearby tissue. A high-grade squamous intraepithelial lesion is sometimes called moderate or severe dysplasia. Also called HSIL.
high-intensity focused ultrasound therapy: (hy-in-TEN-sih-tee FOH-kust UL-truh-sownd THAYR-uh-pee); A procedure in which high-energy sound waves are aimed directly at an area of abnormal cells or tissue in the body. The waves create heat that kills the cells. High-intensity focused ultrasound therapy is being studied in the treatment of prostate cancer and some other types of cancer and other diseases. Also called HIFU.
high-resolution micro-ultrasound: (hy-reh-zuh-LOO-shun MY-kroh-UL-truh-sownd); A procedure that uses high-energy sound waves to create pictures of the prostate and surrounding tissue that are much more detailed than standard ultrasound. This makes it easier to see a suspicious or abnormal area of the prostate and determine if a biopsy is needed. High-resolution micro-ultrasound may also be used during a biopsy to help guide the removal of a sample of abnormal prostate tissue. It may be used to help diagnose prostate cancer, monitor prostate cancer growth over time, and plan treatment.
high-risk cancer: (hy-risk KAN-ser); Cancer that is likely to recur (come back), or spread.
high-risk HPV: (hy-risk …); A group of cancer-causing human papillomaviruses (HPV). These viruses can infect the cells on the moist surfaces or inner lining of some organs and body cavities, such as the cervix, vagina, vulva, penis, anus, mouth, and throat. A long-lasting infection with a high-risk HPV type can cause cell changes that become cancer over time if not found and removed. High-risk HPV can cause cancers of the cervix, anus, oropharynx, vagina, vulva, and penis. There are about 12 types of high-risk HPV, but HPV types 16 and 18 cause most HPV-related cancers. High-risk HPV is transmitted through intimate skin-to-skin contact, most often during vaginal, anal, or oral sex. Also called high-risk human papillomavirus.
high-risk human papillomavirus: (hy-risk HYOO-mun PA-pih-LOH-muh-VY-rus); A group of cancer-causing human papillomaviruses (HPV). These viruses can infect the cells on the moist surfaces or inner lining of some organs and body cavities, such as the cervix, vagina, vulva, penis, anus, mouth, and throat. A long-lasting infection with a high-risk human papillomavirus type can cause cell changes that become cancer over time if not found and removed. High-risk human papillomavirus can cause cancers of the cervix, anus, oropharynx, vagina, vulva, and penis. There are about 12 types of high-risk human papillomavirus, but HPV types 16 and 18 cause most HPV-related cancers. High-risk human papillomavirus is transmitted through intimate skin-to-skin contact, most often during vaginal, anal, or oral sex. Also called high-risk HPV.
high-selenium Brassica juncea: (hy-seh-LEE-nee-um BRA-sih-kuh JUN-see-uh); Brassica juncea that has been grown in high levels of selenium. Brassica juncea is a plant of the cabbage family that has been used in some cultures to treat certain medical problems, including arthritis, colds, stomach disorders, and tumors. The plant stores minerals, including selenium which may stop tumor cells from growing. High-selenium Brassica juncea is being studied in the treatment of cancer. Brassica juncea is also known as Indian mustard.
highly active antiretroviral therapy: (...AN-tee-REH-troh-VY-rul THAYR-uh-pee); Treatment that uses a combination of three or more drugs to treat HIV infection. Highly active antiretroviral therapy stops the virus from making copies of itself in the body. This may lessen the damage to the immune system caused by HIV and may slow down the development of AIDS. It may also help prevent transmission of HIV to others, including from mother to child during birth. Also called cART, combination antiretroviral therapy, and HAART.
hilar: (HY-ler); Refers to the area where nerves and blood vessels attach to an organ.
HIPAA: (HIH-puh); A 1996 U.S. law that allows workers and their families to keep their health insurance when they change or lose their jobs. The privacy rule of the HIPAA protects the privacy of a person’s health information and keeps it from being misused. It gives people the right to receive and review their health records and to choose with whom their health care providers and health insurance companies share their information (including friends, family members, and caregivers). The law also includes standards for setting up and maintaining secure electronic health records. Also called Health Insurance Portability and Accountability Act and Kassebaum Kennedy Act.
HIPEC: A treatment used during surgery in which a heated solution containing anticancer drugs is infused directly into the abdominal cavity through a thin tube. After removal of as much tumor tissue as possible with surgery, HIPEC is given to kill any remaining tumor cells. It is most often used to treat cancers that have spread to the peritoneum (the lining of the abdominal cavity). Also called CHPP, continuous hyperthermic peritoneal perfusion, and hyperthermic intraperitoneal chemotherapy.
Hirschsprung disease: (HIRSH-sprung dih-ZEEZ); A condition in which certain nerve cells are missing from the muscle layers of part of the large intestine. This causes severe constipation or blockage of the large intestine. Constipation is when stool becomes hard, dry, and difficult to pass and bowel movements occur less often than normal. Other symptoms include swollen abdomen, vomiting, bloody diarrhea, gas, lack of energy, and trouble gaining weight. Hirschsprung disease is present from birth, but the symptoms may not appear until later in a child’s life. This condition has been linked to an increased risk of thyroid cancer and neuroblastoma. Also called aganglionic megacolon.
histamine: (HIS-tuh-meen); A substance that has many effects in the body. It is released from some types of white blood cells during allergic reactions. It causes small blood vessels to dilate (widen) and become leaky, which can cause tissues to swell. It also causes smooth muscles to contract, gastric acid to be made, and the heart rate to increase. Histamine is used in tests for allergies, asthma, and gastric acid secretion. It is a type of neurotransmitter.
histamine dihydrochloride: (HIS-tuh-meen dy-HY-droh-KLOR-ide); A substance being studied in the treatment of some types of cancer and other conditions. When used together with interleukin-2, histamine dihydrochloride may help some immune cells find and kill tumor cells. It is a type of biological response modifier. Also called Maxamine.
histiocytic neoplasm: (HIS-tee-oh-SIH-tik NEE-oh-PLA-zum); A group of rare disorders in which too many histiocytes (a type of white blood cell) build up in certain tissues and organs, including the skin, bones, spleen, liver, lungs, and lymph nodes. This can cause damage to tissue or tumors to form in one or more parts of the body. The tumor may be benign (not cancer) or malignant (cancer). There are different types of histiocytic neoplasms, including Langerhans cell histiocytosis (LCH), hemophagocytic lymphohistiocytosis (HLH), and malignant histiocytic disorders. Histiocytic neoplasms occur most often in children, but can occur at any age. Also called histiocytosis.
histiocytoid hemangioma: (HIS-tee-oh-SY-toyd hee-MAN-jee-OH-muh); A rare benign (not cancer) tumor of small blood vessels surrounded by lymphocytes and eosinophils (types of white blood cells). Histiocytoid hemangioma usually forms on or in the skin, especially the skin of the head, but can occur in other areas of the body, such as in bone. On the skin, it may appear as firm pink to red bumps that may be itchy or painful. If the tumor is in bone, it may cause swelling and pain. Histiocytoid hemangioma is sometimes caused by injury and often comes back after treatment. Histiocytoid hemangioma is most common in young and middle-aged adults. It is a type of vascular tumor. Also called angiolymphoid hyperplasia with eosinophilia and epithelioid hemangioma.
histiocytosis: (HIS-tee-oh-sy-TOH-sis); A group of rare disorders in which too many histiocytes (a type of white blood cell) build up in certain tissues and organs, including the skin, bones, spleen, liver, lungs, and lymph nodes. This can cause damage to tissue or tumors to form in one or more parts of the body. The tumor may be benign (not cancer) or malignant (cancer). There are different types of histiocytosis, including Langerhans cell histiocytosis (LCH), hemophagocytic lymphohistiocytosis (HLH), and malignant histiocytic disorders. Histiocytosis occurs most often in children, but can occur at any age. Also called histiocytic neoplasm.
histologic examination: (HIS-tuh-LAH-jik eg-ZA-mih-NAY-shun); The examination of tissue specimens under a microscope.
histologic grade: (HIS-tuh-LAH-jik grayd); A description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread. Low-grade cancer cells look more like normal cells and tend to grow and spread more slowly than high-grade cancer cells. Grading systems are different for each type of cancer. They are used to help plan treatment and determine prognosis. Also called grade and tumor grade.
histology: (his-TAH-loh-jee); The study of tissues and cells under a microscope.
histone: (HIS-tone); A type of protein found in chromosomes. Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.
histone deacetylase: (HIS-tone dee-uh-SEH-tih-lays); An enzyme that removes a small molecule called an acetyl group from histones (proteins found in chromosomes). This changes the way the histones bind to DNA and may affect its activity. Histone deacetylase inhibitors are being studied in the treatment of cancer. Also called HDAC.
histone deacetylase inhibitor: (HIS-tone dee-uh-SEH-tih-lays in-HIH-bih-ter); A substance that causes a chemical change that stops tumor cells from dividing. Histone deacetylase inhibitors are being studied in the treatment of cancer. Also called HDAC inhibitor.
histone methyltransferase inhibitor: (HIS-tone MEH-thul-TRANZ-feh-rays in-HIH-bih-ter); A substance that blocks certain enzymes involved in gene expression and cell division. These enzymes may be found in a mutated (changed) form or at high levels in some types of cancer cells. Blocking them may help keep cancer cells from growing. Histone methyltransferase inhibitors are being studied in the treatment of some types of cancer. They are a type of targeted therapy. Also called HMT inhibitor.
histopathology: (HIS-toh-puh-THAH-loh-jee); The study of diseased cells and tissues using a microscope.
historic cohort study: (hih-STOR-ik KOH-hort STUH-dee); A research study in which the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) are compared for a particular outcome (such as lung cancer). Also called retrospective cohort study.
historical control subject: (hih-STOR-ih-kul kun-TROLE SUB-jekt); An individual treated in the past and used in a comparison group when researchers analyze the results of a clinical study that had no control group. The use of a control, or comparison, group helps researchers determine the effects of a new treatment more accurately.
histrelin acetate: (his-TREH-lin A-seh-tayt); A drug used under the brand name Vantas as palliative therapy for advanced prostate cancer. Histrelin acetate initially causes the pituitary gland to make more luteinizing hormone (LH) and follicle-stimulating hormone (FSH), temporarily increasing testosterone levels in men. With continued use, histrelin acetate lowers the amount of LH and FSH the pituitary gland releases, leading to a drop in testosterone levels. Histrelin acetate is also used under the brand name Supprelin LA to treat early puberty in males and females. It is a type of hormone therapy called a luteinizing hormone-releasing hormone (LHRH) agonist and a type of androgen deprivation therapy that is reversible.
HIV: The cause of acquired immunodeficiency syndrome (AIDS). Also called human immunodeficiency virus.
HIV antibody: (... AN-tee-BAH-dee); A substance produced by certain white blood cells in reaction to contact with the human immunodeficiency virus (HIV).
HIV antibody test: (… AN-tee-BAH-dee …); A test to check for human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). An HIV antibody test checks for HIV antibodies in a sample of blood, urine, or saliva. It can take from 2 weeks to 6 months after a person is infected with HIV before the antibodies are found with this test. It is the most common type of HIV test.
HIV DNA test: A test to check for human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). An HIV DNA test checks for DNA (genetic material) from the virus in a sample of blood. This test can find HIV in the blood about 9-11 days after the person is infected with the virus. An HIV DNA test may be used to test someone who has just become infected with HIV and it may also be used to test for infection in infants born to mothers infected with HIV.
HIV negative: (... NEH-guh-tiv); Refers to a person who is not infected with the human immunodeficiency virus (HIV). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS).
HIV positive: (... PAH-zih-tiv); Refers to a person who is infected with the human immunodeficiency virus (HIV). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS).
HIV RNA test: A test to check for human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). An HIV RNA test checks for RNA (genetic material) from the virus in a sample of blood. This test can find HIV in the blood about 9-11 days after the person is infected with the virus. An HIV RNA test is used to test someone who may have just become infected with HIV.
HIV test: (… test); A test to check for human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). The most common type of HIV test is called the HIV antibody test, which checks for antibodies against HIV in a sample of blood, urine, or fluid from the mouth. It can take from 2 weeks to 6 months after a person is infected with HIV before the antibodies are found with an HIV antibody test. Another type of HIV test checks for RNA or DNA from HIV in a sample of blood. This test can find HIV in a person’s blood about 9-11 days after the person is infected with the virus.
HIV window period: (… WIN-doh PEER-ee-ud); The time period that starts when a person becomes infected with the human immunodeficiency virus (HIV) and ends when the body makes enough antibodies against the virus or HIV DNA or RNA to be found with an HIV test. For the test that looks for antibodies against HIV, the HIV window period can last from 2 weeks to 6 months. For the HIV DNA or RNA test, the HIV window period is about 9-11 days. During the HIV window period, an infected person may have negative HIV test results but still be able to infect other people.
hives: (hyvz); Itchy, raised red areas on the skin. Hives are caused by a reaction to certain foods, drugs, infections, or emotional stress. Also called urticaria.
HLA: A type of molecule found on the surface of most cells in the body. HLAs play an important part in the body's immune response to foreign substances. They make up a person’s tissue type, which varies from person to person. HLA tests are done before a donor stem cell or organ transplant, to find out if tissues match between the donor and the person receiving the transplant. Also called human leukocyte antigen and human lymphocyte antigen.
HLA matching: (… MA-ching); A process in which blood or tissue samples are tested for human leukocyte antigens (HLAs). HLAs are molecules found on the surface of most cells in the body. They make up a person’s tissue type, which varies from person to person. They play an important part in the body's immune response to foreign substances. HLA matching is done before a donor stem cell or organ transplant to find out if tissues match between the donor and the person receiving the transplant. Also called human leukocyte antigen matching.
HLA-A*02:01 antigen: (… AN-tih-jen); A common cell surface marker that is part of the set of HLA antigens that make up a person’s tissue type. HLA antigens are found on the surface of most cells in the body, and they play an important role in the body's immune response to foreign substances. The HLA-A*02:01 antigen is also found on the surface of some types of cancer cells, such as some melanoma cells, which may help trigger the immune system to destroy the cancer cells.
HLH: A rare disorder in which histiocytes and lymphocytes (types of white blood cells) build up in organs including the skin, spleen, and liver, and destroy other blood cells. HLH may be inherited or caused by certain conditions or diseases, including infections, immunodeficiency (inability of the body to fight infections), and cancer. Also called hemophagocytic lymphohistiocytosis.
hLL1: A substance being studied in the treatment of multiple myeloma and several other types of cancer. It binds to CD74, a protein on the surface of myeloma cells and certain other types of cells. It may help kill cancer cells. hLL1 is a type of monoclonal antibody. Also called IMMU-110 and milatuzumab.
HLRCC: A rare, inherited disorder in which benign (not cancer) skin lesions called leiomyomas form in the smooth muscle tissue around the hair follicles. They usually form on the arms, legs, chest, and abdomen. Benign leiomyomas may also form as fibroids in the uterus in females. People with HLRCC have an increased risk of kidney cancer. The signs and symptoms of HLRCC usually do not appear until young adulthood. HLRCC is caused by a mutation in the FH gene. It is inherited in an autosomal dominant manner. Also called hereditary leiomyomatosis and renal cell cancer.
HMG-CoA reductase inhibitor: (HMG-koh-A ree-DUK-tays in-HIH-bih-ter); A substance that blocks an enzyme needed by the body to make cholesterol and lowers the amount of cholesterol in the blood. HMG-CoA reductase inhibitor drugs are called statins. Also called hydroxymethylglutaryl-coenzyme A reductase inhibitor.
HMGA1: A protein that binds to the DNA and certain proteins in chromosomes. It is involved in many functions in the cell, and helps protect cells from dying. HMGA1 is found at high levels in several types of cancer cells.
HMR 1275: A substance being studied in the treatment of several types of cancer. It stops cells from dividing and may kill cancer cells. It is a type of cyclin-dependent kinase (CDK) inhibitor. Also called alvocidib and flavopiridol.
HMT inhibitor: (... in-HIH-bih-ter); A substance that blocks certain enzymes involved in gene expression and cell division. These enzymes may be found in a mutated (changed) form or at high levels in some types of cancer cells. Blocking them may help keep cancer cells from growing. HMT inhibitors are being studied in the treatment of some types of cancer. They are a type of targeted therapy. Also called histone methyltransferase inhibitor.
HNPCC: An inherited disorder that increases the risk of developing colorectal cancer, endometrial cancer, ovarian cancer, and many other types of cancer, such as cancers of the stomach, small intestine, pancreas, bile duct, urinary tract, and brain, often before age 50. HNPCC is caused by mutations (changes) in genes that affect DNA mismatch repair, a process that fixes mistakes that occur when DNA is copied. These genes are MLH1, MSH2, MSH6, PMS2, and EPCAM. Also called hereditary nonpolyposis colorectal cancer and Lynch syndrome.
Hodgkin and Reed-Sternberg cell: (HOJ-kin ... reed-STERN-berg sel); A type of cell that appears in people with Hodgkin disease. The number of these cells increases as the disease advances. Also called Reed-Sternberg cell.
Hodgkin disease: (HOJ-kin dih-ZEEZ); A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The two major types of Hodgkin disease are classic Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Signs and symptoms include painless, swollen lymph nodes, an enlarged spleen, fever, weight loss, fatigue, and night sweats. Also called Hodgkin lymphoma.
Hodgkin lymphoma: (HOJ-kin lim-FOH-muh); A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The two major types of Hodgkin lymphoma are classic Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Signs and symptoms include painless, swollen lymph nodes, an enlarged spleen, fever, weight loss, fatigue, and night sweats. Also called Hodgkin disease.
holy thistle: (... THIH-sul); A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Holy thistle may have anti-inflammatory and anticancer effects. The scientific name is Cnicus benedictus. Also called blessed thistle, cardin, spotted thistle, and St. Benedict's thistle.
homeopathic medicine: (HOH-mee-uh-PA-thik MEH-dih-sin); An alternative approach to medicine based on the belief that natural substances, prepared in a special way and used most often in very small amounts, restore health. According to these beliefs, in order for a remedy to be effective, it must cause in a healthy person the same symptoms being treated in the patient. Also called homeopathy.
homeopathy: (HOH-mee-AH-puh-thee); An alternative approach to medicine based on the belief that natural substances, prepared in a special way and used most often in very small amounts, restore health. According to these beliefs, in order for a remedy to be effective, it must cause in a healthy person the same symptoms being treated in the patient. Also called homeopathic medicine.
homeostasis: (HOH-mee-oh-STAY-sis); A state of balance among all the body systems needed for the body to survive and function correctly. In homeostasis, body levels of acid, blood pressure, blood sugar, electrolytes, energy, hormones, oxygen, proteins, and temperature are constantly adjusted to respond to changes inside and outside the body, to keep them at a normal level.
homeostatic: (HOH-mee-oh-STA-tik); Having to do with homeostasis, which is a state of balance among all the body systems, needed for the body to function correctly.
homoharringtonine: (hoh-moh-HAYR-ing-tuh-neen); A drug used to treat adults with certain types of chronic myelogenous leukemia that cannot be treated with tyrosine kinase inhibitors (a type of anticancer drug) or that have not gotten better after treatment with at least two tyrosine kinase inhibitors. It is also being studied in the treatment of other types of cancer. Homoharringtonine blocks certain proteins involved in cell growth and may kill cancer cells. It is a type of plant alkaloid and a type of protein synthesis inhibitor. Also called omacetaxine mepesuccinate and Synribo.
homologous recombination repair pathway: (hoh-MAH-luh-gus ree-KOM-bih-NAY-shun reh-PAYR PATH-way); Describes a process in a cell in which a group of proteins work together to repair DNA damage. Changes in the homologous recombination repair pathway that result in the inability to repair DNA may lead to diseases such as cancer. Drugs that affect this pathway are being studied in the prevention and treatment of cancer and other diseases. Also called HRR pathway.
homozygous genotype: (HOH-moh-ZY-gus JEE-noh-tipe); A term that describes having two identical versions of the same gene (one inherited from the mother and one inherited from the father). In a homozygous genotype, either both genes are normal or both genes have the same mutation (change). For example, a person who inherits the same mutation in both copies of the LDLR gene is homozygous for that gene and will develop a severe form of familial hypercholesterolemia (very high levels of cholesterol in the blood).
hookah: (HOOK-uh); A device used to smoke a special type of tobacco that comes in different flavors. In a hookah, charcoal is used to heat the tobacco. The smoke from the heated tobacco is cooled by passing it through a water-filled bowl. It is then inhaled through a flexible tube with a mouthpiece. Hookah tobacco smoke contains nicotine and many cancer-causing chemicals that are harmful to both smokers and nonsmokers. Hookah smoking can lead to nicotine addiction and can cause many of the same health problems as cigarette smoking. Hookah smoking is not safer than cigarette smoking. Also called water pipe.
hormonal contraception: (hor-MOH-nul KON-truh-SEP-shun); A type of birth control that uses hormones to prevent pregnancy. Hormonal contraceptives contain estrogen and progesterone, or progesterone only. They prevent pregnancy by blocking the release of eggs from the ovaries, thinning the lining of the uterus, or thickening the mucus in the cervix to help keep sperm from reaching the egg. Hormonal contraceptives may be taken by mouth, injected or inserted under the skin, placed on the skin as a patch, or placed in the vagina or uterus.
hormonal therapy: (hor-MOH-nul THAYR-uh-pee); Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. Hormones can also cause certain cancers (such as prostate and breast cancer) to grow. To slow or stop the growth of cancer, synthetic hormones or other drugs may be given to block the body’s natural hormones, or surgery is used to remove the gland that makes a certain hormone. Also called endocrine therapy, hormone therapy, and hormone treatment.
hormone: (HOR-mone); One of many substances made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.
hormone receptor: (HOR-mone reh-SEP-ter); A cell protein that binds a specific hormone. The hormone receptor may be on the surface of the cell or inside the cell. Many changes take place in a cell after a hormone binds to its receptor.
hormone receptor negative: (HOR-mone reh-SEP-ter NEH-guh-tiv); Describes cells that do not have a group of proteins that bind to a specific hormone. For example, some breast cancer cells do not have receptors for the hormones estrogen or progesterone. These cells are hormone receptor negative and they do not need estrogen or progesterone to grow. This can affect how the cancer is treated. Knowing if the cancer is hormone receptor negative may help plan treatment.
hormone receptor positive: (HOR-mone reh-SEP-ter PAH-zih-tiv); Describes cells that have a group of proteins that bind to a specific hormone. For example, some breast cancer cells have receptors for the hormones estrogen or progesterone. These cells are hormone receptor positive and they need estrogen or progesterone to grow. This can affect how the cancer is treated. Knowing if the cancer is hormone receptor positive may help plan treatment.
hormone receptor status: (HOR-mone reh-SEP-ter STA-tus); A term used to describe whether cells have proteins called hormone receptors that bind to a specific hormone. For example, breast cancer cells that have receptors for the hormone estrogen are called estrogen receptor positive and may need estrogen to grow. Knowing the hormone receptor status of the cancer may help plan treatment.
hormone receptor test: (HOR-mone reh-SEP-ter test); A test to measure the amount of certain proteins, called hormone receptors, in cancer tissue. Hormones can attach to these proteins. A high level of hormone receptors may mean that hormones help the cancer grow.
hormone replacement therapy: (HOR-mone reh-PLAYS-ment THAYR-uh-pee); Treatment with hormones to replace natural hormones when the body does not make enough. For example, hormone replacement therapy may be given when the thyroid gland does not make enough thyroid hormone or when the pituitary gland does not make enough growth hormone. Or, it may be given to women after menopause to replace the hormones estrogen and progesterone that are no longer made by the body. Also called HRT.
hormone responsive: (HOR-mone reh-SPONT-siv); In oncology, describes cancer that responds to hormone treatment.
hormone therapy: (HOR-mone THAYR-uh-pee); Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. Hormones can also cause certain cancers (such as prostate and breast cancer) to grow. To slow or stop the growth of cancer, synthetic hormones or other drugs may be given to block the body’s natural hormones, or surgery is used to remove the gland that makes a certain hormone. Also called endocrine therapy, hormonal therapy, and hormone treatment.
hormone treatment: (HOR-mone TREET-ment); Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. Hormones can also cause certain cancers (such as prostate and breast cancer) to grow. To slow or stop the growth of cancer, synthetic hormones or other drugs may be given to block the body’s natural hormones, or surgery is used to remove the gland that makes a certain hormone. Also called endocrine therapy, hormonal therapy, and hormone therapy.
hormone-refractory: (HOR-mone-reh-FRAK-tor-ee); In medicine, describes a disease or condition that does not respond to treatment with hormones. Also called hormone-resistant.
hormone-resistant: (HOR-mone-reh-ZIH-stunt); In medicine, describes a disease or condition that does not respond to treatment with hormones. Also called hormone-refractory.
hormone-sensitive prostate cancer: (HOR-mone-SEN-sih-tiv PROS-tayt KAN-ser); Prostate cancer that needs androgens (male hormones) to grow and therefore stops growing when androgens are not present. Many early-stage prostate cancers are androgen-dependent, so reducing the amount of androgens in the body or blocking their action may be an effective type of therapy. Also called androgen-dependent prostate cancer, androgen-sensitive prostate cancer, castrate-sensitive prostate cancer, CSPC, and HSPC.
Horner syndrome: (...SIN-drome); A condition in which one side of the face is flushed, does not produce sweat, and has a constricted pupil and drooping eyelid. It can be caused by an injury to, or paralysis of, nerves in the neck, or by a tumor.
hospice: (HOS-pis); A program that gives special care to people who are near the end of life and have stopped treatment to cure or control their disease. Hospice offers physical, emotional, social, and spiritual support for patients and their families. The main goal of hospice care is to control pain and other symptoms of illness so patients can be as comfortable and alert as possible. It is usually given at home, but may also be given in a hospice center, hospital, or nursing home.
hospice center: (HOS-pis SEN-ter); A place that provides special care for people who are near the end of life and have stopped treatment to cure or control their disease. Hospice centers provide physical, emotional, social, and spiritual support for patients and their families. They provide care for patients whose pain and other symptoms cannot be managed safely and comfortably at home or who do not have a caregiver at home. Hospice centers may also provide respite care (short-term care for a patient so that the usual caregiver can have a break).
hospitalist: (HOS-pih-tuh-list); A medical doctor who manages and coordinates the daily medical care of patients while they are in the hospital. A hospitalist may also supervise and teach medical students, interns, and residents. A patient’s personal doctor will work with a hospitalist to care for his or her patient while the patient is in the hospital.
host cell: (... sel); A cell that is infected by a virus or another type of microorganism.
hot flash: (hot flash); A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).
hot nodule: (hot NAH-jool); When radioactive material is used to examine the thyroid with a scanner, nodules that collect more radioactive material than the surrounding thyroid tissue are considered "hot." Hot nodules are rarely malignant. Hot nodules are sometimes called hyperfunctioning nodules.
hot tumor: (hot TOO-mer); Describes a tumor that is likely to trigger a strong immune response. Hot tumors often have many molecules on their surface that allow T cells (a type of immune cell) to attack and kill the tumor cells. Hot tumors usually respond to immunotherapy. Melanoma, non-small cell lung cancer, and cancers of the bladder, head and neck, kidney, and liver are usually considered hot tumors.
hotspot: (hot-spot); In genetics, an area of DNA that is likely to mutate (change).
HPPH: 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a. A drug that is used in photodynamic therapy that is absorbed by tumor cells; when exposed to light, it becomes active and kills the cancer cells.
HPRC: A rare, inherited disorder that increases the risk of a type of kidney cancer called type 1 papillary kidney cancer. This cancer forms in cells that line the small tubes in the kidney that filter waste from the blood and make urine. HPRC often affects both kidneys, and often there is more than one tumor in each kidney. It is caused by mutations (changes) in a gene called MET. HPRC is a type of hereditary cancer syndrome. Also called hereditary papillary renal cancer and hereditary papillary renal carcinoma.
HPV: A group of more than 200 common viruses. Some HPVs, called cutaneous HPVs, are transmitted by casual contact and can infect the skin and cause common skin warts. Other HPVs, known as mucosal HPVs, can infect the moist surfaces or inner lining of some organs and body cavities, such as the cervix, vagina, vulva, penis, anus, mouth, and throat. Infection with some mucosal HPVs (collectively known as low-risk HPVs) can cause warts in or around the genitals, anus, mouth, and respiratory tract but rarely cause cancer. Long-lasting infection with other mucosal HPVs (collectively known as high-risk HPVs) can cause cell changes that become cancer over time if not found and removed. HPV-related cancers include cancers of the cervix, anus, oropharynx, vagina, vulva, and penis. Mucosal HPVs are transmitted through intimate skin-to-skin contact, most often during vaginal, anal, or oral sex. Also called human papillomavirus.
HPV 16: A type of HPV that is transmitted sexually and causes cancers of the cervix, anus, oropharynx (the middle part of the throat, behind the mouth), vagina, vulva, and penis. A long-lasting infection with HPV 16 can cause cell changes that, if not treated, may worsen over time and become cancer. HPV 16 and HPV 18 are responsible for most HPV-related cancers. Also called human papillomavirus 16.
HPV 18: A type of HPV that is transmitted sexually and causes cancers of the cervix, anus, oropharynx (the middle part of the throat, behind the mouth), vagina, vulva, and penis. A long-lasting infection with HPV 18 can cause cell changes that, if not treated, may worsen over time and become cancer. HPV 18 and HPV 16 are responsible for most HPV-related cancers. Also called human papillomavirus 18.
HPV DNA test: (... test); A laboratory test in which cells are scraped from the cervix to look for DNA of human papillomaviruses (HPV). HPV can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV can cause cervical cancer. HPV can also play a role in other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called human papillomavirus DNA test.
HPV RNA test: (… test); A laboratory test in which cells are scraped from the cervix to look for RNA of the most common types of human papillomavirus (HPV). Certain types of HPV may cause abnormal tissue growth, such as warts, and other changes to cells. Infection for a long time with other types of HPV may cause cervical cancer. An HPV RNA test may be done with a Pap test to check for HPV infection and cervical cancer. HPV infection may also cause other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called human papillomavirus RNA test.
HPV test: A laboratory test in which cells are tested for DNA or RNA from certain types of human papillomavirus (HPV) that are known to cause cervical cancer. These high-risk types of HPV can also cause other types of cancer, including cancers of the anus, vagina, vulva, penis, and oropharynx. An HPV test may be used alone for cervical cancer screening (also called primary HPV testing), or it can be done at the same time as a Pap test (called cotesting). An HPV test may also be done after certain abnormal Pap test results. Also called human papillomavirus test.
HPV vaccine: (... vak-SEEN); A vaccine that helps protect the body against infection with certain types of human papillomavirus (HPV). HPV infection can cause abnormal tissue growth, such as warts, and other changes to cells. Infection for a long time with certain types of HPV can cause cancers of the cervix, vagina, vulva, anus, penis, and oropharynx. HPV vaccines are being used to prevent some of these cancers. They are also being used to prevent genital warts and abnormal lesions that may lead to some of these cancers. Also called human papillomavirus vaccine.
HPV/Pap cotest: A procedure in which a human papillomavirus (HPV) test and a Pap test are done at the same time to check for cervical cancer. The HPV test looks for DNA or RNA from certain high-risk types of HPV in samples of cells taken from the cervix. The Pap test checks for cervical cancer cells and cell changes that may lead to cervical cancer. The same cell sample may be used for both the HPV test and the Pap test. Women aged 30 to 65 years may have an HPV/Pap cotest every 5 years. Cotesting is more likely to find abnormal cells or cervical cancer than a Pap test alone is. Also called Pap/HPV cotest.
HRAS gene: (… jeen); A gene that makes a protein that is involved in cell signaling pathways that control cell growth and cell death. Mutated (changed) forms of the HRAS gene may be found in some types of cancer. These changes may cause cancer cells to grow and spread in the body.
HRR pathway: (… PATH-way); Describes a process in a cell in which a group of proteins work together to repair DNA damage. Changes in the HRR pathway that result in the inability to repair DNA may lead to diseases such as cancer. Drugs that affect this pathway are being studied in the prevention and treatment of cancer and other diseases. Also called homologous recombination repair pathway.
HRT: Treatment with hormones to replace natural hormones when the body does not make enough. For example, HRT may be given when the thyroid gland does not make enough thyroid hormone or when the pituitary gland does not make enough growth hormone. Or, it may be given to women after menopause to replace the hormones estrogen and progesterone that are no longer made by the body. Also called hormone replacement therapy.
HSIL: An area of abnormal cells that forms on the surface of certain organs, such as the cervix, vagina, vulva, anus, and esophagus. HSILs look somewhat to very abnormal when looked at under a microscope. They are usually caused by chronic infection with certain types of human papillomavirus (HPV) and are found when a Pap test or biopsy is done. If not treated, these abnormal cells may become cancer and spread into nearby tissue. A HSIL is sometimes called moderate or severe dysplasia. Also called high-grade squamous intraepithelial lesion.
HSP: One of a group of proteins that help protect cells from stresses such as heat, cold, and low amounts of oxygen or glucose (sugar). HSPs help other proteins function in normal cells and may be present at high levels in cancer cells. Blocking the activity of a HSP called HSP90 is being studied in the treatment of cancer. Other HSPs including HSP70 and gp96 are being studied in vaccines to treat cancer. Also called heat-shock protein and stress protein.
HSPC: Prostate cancer that needs androgens (male hormones) to grow and therefore stops growing when androgens are not present. Many early-stage prostate cancers are androgen-dependent, so reducing the amount of androgens in the body or blocking their action may be an effective type of therapy. Also called androgen-dependent prostate cancer, androgen-sensitive prostate cancer, castrate-sensitive prostate cancer, CSPC, and hormone-sensitive prostate cancer.
HSV: A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of HSVs. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called herpes simplex virus, HHV, and human herpesvirus.
HTLV-1: A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. HTLV-1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding. Also called human T-cell leukemia virus type 1 and human T-cell lymphotropic virus type 1.
hu14.18-interleukin-2 fusion protein: (… in-ter-LOO-kin-2 FYOO-zhun PROH-teen); An anticancer drug in which hu14.18, a monoclonal antibody, is combined with interleukin-2. The monoclonal antibody binds to the cancer cells and delivers IL-2, which stimulates the immune system to destroy the cancer cells.
Hu3S193: A monoclonal antibody that is being studied in the treatment of some types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Hu3S193 binds to the protein Lewis(y), which is found on colon, breast, lung, ovary, and prostate cancer cells.
HuAFP31: A monoclonal antibody being studied in the treatment of several types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. HuAFP31 attaches to tumor cells that make alpha fetoprotein (AFP). This makes it easier for T cells to find and kill the tumor cells.
Huang Lian: (hwang lyan); A Chinese herb that has been used as a treatment for a variety of medical problems. It is being studied as an anticancer drug.
huC242-DM4: A substance being studied in the treatment of some types of cancer. It is made by linking the monoclonal antibody huC242 to a toxic substance called maytansinoid DM4. The monoclonal antibody binds to the surfaces of cancer cells and the maytansinoid DM4 enters the cells and blocks their growth. It is a type of immunotoxin. Also called maytansinoid DM4-conjugated humanized monoclonal antibody huC242.
HuHMFG1: A monoclonal antibody that binds to the protein MUC1, which is found on breast, ovarian, pancreatic, gastric, and colon cancer cells. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. HuHMFG1 is being studied in the treatment of some types of cancer.
HuLuc63: A drug used with dexamethasone and either lenalidomide or pomalidomide to treat adults with multiple myeloma. It is used in patients whose cancer was already treated with other anticancer therapies. HuLuc63 binds to a protein called CS1, which is found on myeloma cells and some types of immune cells. HuLuc63 may block CS1 and help the immune system kill cancer cells. It is a type of monoclonal antibody. Also called elotuzumab and Empliciti.
human corticotropin-releasing factor: (HYOO-mun KOR-tih-koh-TROH-pin-reh-LEE-sing FAK-ter); A substance being studied in the treatment of brain cancer. It is made naturally by the hypothalamus (a part of the brain) and can also be made in the laboratory. Human corticotropin-releasing factor may help reduce symptoms caused by edema (swelling) of the brain. It is a type of neurohormone. Also called hCRF.
human EGF receptor 2: (HYOO-mun … reh-SEP-ter ...); A protein involved in normal cell growth. Human EGF receptor 2 may be made in larger than normal amounts by some types of cancer cells, including breast, ovarian, bladder, pancreatic, stomach, and esophageal cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. Checking the amount of human EGF receptor 2 on some types of cancer cells may help plan treatment. Also called c-erbB-2, HER2, HER2/neu, and human epidermal growth factor receptor 2.
human epidermal growth factor receptor 2: (HYOO-mun eh-pih-DER-mul grothe FAK-ter reh-SEP-ter ...); A protein involved in normal cell growth. Human epidermal growth factor receptor 2 may be made in larger than normal amounts by some types of cancer cells, including breast, ovarian, bladder, pancreatic, stomach, and esophageal cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. Checking the amount of human epidermal growth factor receptor 2 on some types of cancer cells may help plan treatment. Also called c-erbB-2, HER2, HER2/neu, and human EGF receptor 2.
human epidermal growth factor receptor 2 negative: (HYOO-mun eh-pih-DER-mul grothe FAK-ter reh-SEP-ter … NEH-guh-tiv); Describes cells that have a small amount or none of a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. Cancer cells that are human epidermal growth factor receptor 2 negative may grow more slowly and are less likely to recur (come back) or spread to other parts of the body than cancer cells that have a large amount of HER2 on their surface. Checking to see if a cancer is human epidermal growth factor receptor 2 negative may help plan treatment. Cancers that may be human epidermal growth factor receptor 2 negative include breast, bladder, ovarian, pancreatic, and stomach cancers. Also called HER2 negative.
human epidermal growth factor receptor 2 positive: (HYOO-mun eh-pih-DER-mul grothe FAK-ter reh-SEP-ter … PAH-zih-tiv); Describes cells that have a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. Cancer cells that make too much HER2 may grow more quickly and are more likely to spread to other parts of the body. Checking to see if a cancer is human epidermal growth factor receptor 2 positive may help plan treatment, which may include drugs that kill human epidermal growth factor receptor 2-positive cancer cells. Cancers that may be human epidermal growth factor receptor 2 positive include breast, bladder, pancreatic, ovarian, and stomach cancers. Also called c-erbB-2 positive and HER2 positive.
human epidermal growth factor receptor 2 test: (HYOO-mun eh-pih-DER-mul grothe FAK-ter reh-SEP-ter 2 …); A laboratory test that measures the amount of HER2 protein on cancer cells or how many copies of the HER2 gene are in the DNA of cancer cells. The HER2 protein helps control normal cell growth. Larger than normal amounts of the HER2 protein or too many copies of the HER2 gene may be made by some types of cancer, including breast, ovarian, bladder, pancreatic, and stomach cancers. This may cause cancer cells to grow more quickly and spread to other parts of the body. A human epidermal growth factor receptor 2 test may be done to help plan treatment, which may include drugs that target the HER2 protein. It is a type of tumor marker test. Also called HER2 test and HER2/neu test.
human epididymis protein 4: (HYOO-mun eh-pih-DIH-dih-mis PROH-teen …); A protein found on cells that line the lungs and reproductive organs, such as the ovaries. Human epididymis protein 4 may be found in higher than normal amounts in patients with some types of cancer, including ovarian epithelial cancer. Measuring the amount of human epididymis protein 4 in the blood may help plan cancer treatment or find out if cancer is getting worse or has come back. It is a type of tumor marker. Also called HE4.
human herpesvirus: (HYOO-mun HER-peez-VY-rus); A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of human herpesviruses. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called herpes simplex virus, HHV, and HSV.
human herpesvirus 8: (HYOO-mun HER-peez-VY-rus...); A type of virus that causes Kaposi sarcoma (a rare cancer in which lesions grow in the skin, lymph nodes, lining of the mouth, nose, and throat, and other tissues of the body). Human herpesvirus 8 also causes certain types of lymphoma (cancer that begins in cells of the immune system). Also called HHV8, Kaposi sarcoma-associated herpesvirus, and KSHV.
human immunodeficiency virus: (HYOO-mun IH-myoo-noh-deh-FIH-shun-see VY-rus); The cause of acquired immunodeficiency syndrome (AIDS). Also called HIV.
human leukocyte antigen: (HYOO-mun LOO-koh-site AN-tih-jen); A type of molecule found on the surface of most cells in the body. Human leukocyte antigens play an important part in the body's immune response to foreign substances. They make up a person’s tissue type, which varies from person to person. Human leukocyte antigen tests are done before a donor stem cell or organ transplant, to find out if tissues match between the donor and the person receiving the transplant. Also called HLA and human lymphocyte antigen.
human leukocyte antigen matching: (HYOO-mun LOO-koh-site AN-tih-jen MA-ching); A process in which blood or tissue samples are tested for human leukocyte antigens (HLAs). HLAs are molecules found on the surface of most cells in the body. They make up a person’s tissue type, which varies from person to person. They play an important part in the body's immune response to foreign substances. Human leukocyte antigen matching is done before a donor stem cell or organ transplant to find out if tissues match between the donor and the person receiving the transplant. Also called HLA matching.
human lymphocyte antigen: (HYOO-mun LIM-foh-site AN-tih-jen); A type of molecule found on the surface of most cells in the body. Human lymphocyte antigens play an important part in the body's immune response to foreign substances. They make up a person’s tissue type, which varies from person to person. Human lymphocyte antigen tests are done before a donor stem cell or organ transplant, to find out if tissues match between the donor and the person receiving the transplant. Also called HLA and human leukocyte antigen.
human papillomavirus: (HYOO-mun PA-pih-LOH-muh-VY-rus); A group of more than 200 common viruses. Some human papillomaviruses, called cutaneous human papillomaviruses, are transmitted by casual contact and can infect the skin and cause common skin warts. Other human papillomaviruses, known as mucosal human papillomaviruses, can infect the moist surfaces or inner lining of some organs and body cavities, such as the cervix, vagina, vulva, penis, anus, mouth, and throat. Infection with some mucosal human papillomaviruses (collectively known as low-risk human papillomaviruses) can cause warts in or around the genitals, anus, mouth, and respiratory tract but rarely cause cancer. Long-lasting infection with other mucosal human papillomaviruses (collectively known as high-risk human papillomaviruses) can cause cell changes that become cancer over time if not found and removed. Human papillomavirus-related cancers include cancers of the cervix, anus, oropharynx, vagina, vulva, and penis. Mucosal human papillomaviruses are transmitted through intimate skin-to-skin contact, most often during vaginal, anal, or oral sex. Also called HPV.
human papillomavirus 16: (HYOO-mun PA-pih-LOH-muh-VY-rus …); A type of HPV that is transmitted sexually and causes cancers of the cervix, anus, oropharynx (the middle part of the throat, behind the mouth), vagina, vulva, and penis. A long-lasting infection with human papillomavirus 16 can cause cell changes that, if not treated, may worsen over time and become cancer. Human papillomavirus 16 and HPV 18 are responsible for most HPV-related cancers. Also called HPV 16.
human papillomavirus 18: (HYOO-mun PA-pih-LOH-muh-VY-rus …); A type of HPV that is transmitted sexually and causes cancers of the cervix, anus, oropharynx (the middle part of the throat, behind the mouth), vagina, vulva, and penis. A long-lasting infection with human papillomavirus 18 can cause cell changes that, if not treated, may worsen over time and become cancer. Human papillomavirus 18 and HPV 16 are responsible for most HPV-related cancers. Also called HPV 18.
human papillomavirus DNA test: (HYOO-mun PA-pih-LOH-muh-VY-rus …); A laboratory test in which cells are scraped from the cervix to look for DNA of human papillomaviruses (HPV). HPV can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV can cause cervical cancer. HPV can also play a role in other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called HPV DNA test.
human papillomavirus RNA test: (HYOO-mun PA-pih-LOH-muh-VY-rus … test); A laboratory test in which cells are scraped from the cervix to look for RNA of the most common types of human papillomavirus (HPV). Certain types of HPV may cause abnormal tissue growth, such as warts, and other changes to cells. Infection for a long time with other types of HPV may cause cervical cancer. A human papillomavirus RNA test may be done with a Pap test to check for HPV infection and cervical cancer. HPV infection may also cause other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called HPV RNA test.
human papillomavirus test: (HYOO-mun PA-pih-LOH-muh-VY-rus …); A laboratory test in which cells are tested for DNA or RNA from certain types of human papillomavirus (HPV) that are known to cause cervical cancer. These high-risk types of HPV can also cause other types of cancer, including cancers of the anus, vagina, vulva, penis, and oropharynx. A human papillomavirus test may be used alone for cervical cancer screening (also called primary HPV testing), or it can be done at the same time as a Pap test (called cotesting). A human papillomavirus test may also be done after certain abnormal Pap test results. Also called HPV test.
human papillomavirus vaccine: (HYOO-mun PA-pih-LOH-muh-VY-rus vak-SEEN); A vaccine that helps protect the body against infection with certain types of human papillomavirus (HPV). HPV infection can cause abnormal tissue growth, such as warts, and other changes to cells. Infection for a long time with certain types of HPV can cause cancers of the cervix, vagina, vulva, anus, penis, and oropharynx. Human papillomavirus vaccines are being used to prevent some of these cancers. They are also being used to prevent genital warts and abnormal lesions that may lead to some of these cancers. Also called HPV vaccine.
human participant protection regulations: (HYOO-mun par-TIH-sih-punt proh-TEK-shun REH-gyoo-LAY-shunz); Laws set by the U.S. Department of Health and Human Services (DHHS) to protect a person from risks in research studies that any federal agency or department has a part in. Also called 45 CFR 46, 45 Code of Federal Regulations Part 46, and Protection of Human Subjects.
human T-cell leukemia virus type 1: (HYOO-mun T-sel loo-KEE-mee-uh VY-rus...); A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. Human T-cell leukemia virus type 1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding. Also called HTLV-1 and human T-cell lymphotropic virus type 1.
human T-cell lymphotropic virus type 1: (HYOO-mun T-sel LIM-foh-TROH-pik VY-rus...); A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. Human T-cell lymphotropic virus type 1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding. Also called HTLV-1 and human T-cell leukemia virus type 1.
humanized monoclonal antibody: (HYOO-muh-nized MAH-noh-KLOH-nul AN-tee-BAH-dee); A type of antibody made in the laboratory by combining a human antibody with a small part of a mouse or rat monoclonal antibody. The mouse or rat part of the antibody binds to the target antigen, and the human part makes it less likely to be destroyed by the body's immune system.
humanized monoclonal antibody MEDI-522: (HYOO-muh-nized MAH-noh-KLOH-nul AN-tee-BAH-dee …); A substance being studied in the treatment of some types of cancer and other conditions. Humanized monoclonal antibody MEDI-522 binds to a protein on the surface of blood vessels and may prevent the growth of new blood vessels that tumors need to grow. It may also prevent the spread of cancer. It is a type of antiangiogenesis agent, a type of metastasis inhibitor, and a type of monoclonal antibody. Also called Abegrin, etaracizumab, and MEDI-522.
HuMax-CD20: A drug used alone or with other drugs to treat certain types of chronic lymphocytic leukemia. It is also being studied in the treatment of other types of cancer. HuMax-CD20 binds to a protein called CD20, which is found on B cells (a type of white blood cell) and some types of leukemia and lymphoma cells. HuMax-CD20 may block CD20 and help the immune system kill cancer cells. It is a type of monoclonal antibody. Also called Arzerra and ofatumumab.
humidifier: (hyoo-MIH-dih-fy-er); A machine that puts moisture in the air.
humor therapy: (HYOO-mer THAYR-uh-pee); A type of therapy that uses humor to help relieve pain and stress and improve a person’s sense of well-being. It may be used to help people cope with a serious disease, such as cancer. Humor therapy may include laughter exercises, clowns, and comedy movies, books, games, and puzzles. It is a type of complementary therapy. Also called laughter therapy.
Hurthle cell neoplasm: (HEERT-leh...NEE-oh-PLA-zum); An uncommon type of thyroid tumor that can be benign or malignant.
hyaluronidase: (HY-al-yoo-RAH-nih-days); An enzyme that breaks down a substance in the body called hyaluronic acid. Hyaluronic acid is found throughout the body in connective tissue, skin, and fluids in the joints and inside the eye. It causes fluids to have a jelly-like thickness, which can help moisten and protect tissues and joints. In medicine, hyaluronidase is made in the laboratory and given with other drugs by injection under the skin to treat certain conditions. Using hyaluronidase to break down hyaluronic acid helps make the fluids and connective tissue thinner so the drugs can move more easily into the tissues.
Hycamtin: (hy-KAM-tin); A drug used alone or with other drugs to treat certain types of ovarian cancer, small cell lung cancer, and cervical cancer. It is also being studied in the treatment of other types of cancer. Hycamtin blocks a certain enzyme needed for cell division and DNA repair, and it may kill cancer cells. It is a type of topoisomerase inhibitor and a type of camptothecin analog. Also called topotecan hydrochloride.
hydatidiform mole: (HY-duh-TIH-dih-form...); A slow-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta) after fertilization of an egg by a sperm. A hydatidiform mole contains many cysts (sacs of fluid). It is usually benign (not cancer) but it may spread to nearby tissues (invasive mole). It may also become a malignant tumor called choriocarcinoma. Hydatidiform mole is the most common type of gestational trophoblastic tumor. Also called molar pregnancy.
hydration: (hy-DRAY-shun); The process of combining with water. In medicine, the process of giving fluids needed by the body.
hydrazine sulfate: (HY-druh-ZEEN SUL-fayt); A substance that has been studied as a treatment for cancer and as a treatment for cachexia (body wasting) associated with advanced cancer.
Hydrea: (hy-DREE-uh); A drug that contains the active ingredient hydroxyurea and is used alone or with other anticancer drugs or radiation therapy to treat certain types of chronic myelogenous leukemia and head and neck cancer. It is also being studied in the treatment of other conditions and types of cancer. Hydrea stops cells from making DNA and may kill cancer cells. It may also make cancer cells easier to kill with radiation therapy. Hydrea is a type of antimetabolite.
hydrocarbon: (HY-droh-KAR-bun); A substance made of only hydrogen and carbon. Examples of hydrocarbons are coal, petroleum, natural gas and tar. They are used as energy sources. Being exposed to hydrocarbons may increase the risk of certain types of cancer.
hydrocephalus: (HY-droh-SEH-fuh-lus); The abnormal buildup of cerebrospinal fluid in the ventricles of the brain.
hydrocodone bitartrate: (HY-droh-KOH-done by-TAR-trayt); A drug used to treat moderate to severe pain and cough. Hydrocodone bitartrate is made in a lab by modifying codeine, a natural substance found in the opium poppy plant. It works by binding to mu opioid receptors in the central nervous system, which blocks pain signals and changes how the body responds to pain. It also helps decrease activity in the part of the brain that causes coughing. Hydrocodone bitartrate is a type of antitussive (cough suppressant) and a type of semi-synthetic opioid agonist that works as an analgesic (pain reliever).
hydrocortisone: (HY-droh-KOR-tih-sone); A drug used to relieve the symptoms of certain hormone shortages and to suppress an immune response.
hydrogen cyanide: (HY-droh-jen SY-uh-nide); A liquid or gas form of cyanide. Cyanide is a poisonous chemical found in some foods and plants, tobacco smoke, and when certain substances are burned. It is used to make products, such as paper, fabric, and plastic, and is used as a pesticide. Cyanide keeps cells in the body from using oxygen, so they die. Exposure to cyanide may cause serious health problems, including death.
hydrogen peroxide: (HY-droh-jen peh-ROK-side); A chemical used in bleaches, dyes, cleansers, antiseptics, and disinfectants. In a concentrated form, it is toxic and irritating to tissues.
hydrolysis: (hy-DRAH-lih-sis); A chemical reaction that uses water to break down a compound.
hydromorphone hydrochloride: (HY-droh-MOR-fone HY-droh-KLOR-ide); A drug used to treat moderate to severe pain. It may also be used to treat certain types of cough. Hydromorphone hydrochloride is made from morphine and binds to opioid receptors in the central nervous system. It is a type of opioid and a type of analgesic agent. Also called Dilaudid, Exalgo, and Hydrostat IR.
hydronephrosis: (HY-droh-neh-FROH-sis); Abnormal enlargement of a kidney, which may be caused by blockage of the ureter (such as by a kidney stone) or chronic kidney disease that prevents urine from draining into the bladder.
Hydrostat IR: (HY-droh-STAT …); A drug used to treat moderate to severe pain. It may also be used to treat certain types of cough. Hydrostat IR is made from morphine and binds to opioid receptors in the central nervous system. It is a type of opioid and a type of analgesic agent. Also called Dilaudid, Exalgo, and hydromorphone hydrochloride.
hydroureter: (HY-droh-YER-eh-ter); Abnormal enlargement of the ureter caused by any blockage that prevents urine from draining into the bladder.
hydroxychloroquine: (hy-DROK-see-KLOR-oh-kwin); A substance that decreases immune responses in the body. It is used to treat some autoimmune diseases, and is being studied as a treatment for graft-versus-host disease. Hydroxychloroquine belongs to the family of drugs called antiprotozoals.
hydroxydaunorubicin: (hy-DROK-see-DAW-noh-ROO-bih-sin); A drug that comes from the bacterium Streptomyces peucetius and is used alone or with other drugs to treat many types of cancer, including leukemia, lymphoma, neuroblastoma, sarcoma, Wilms tumor, and certain cancers of the lung, breast, stomach, ovary, thyroid, and bladder. It is also being studied in the treatment of other types of cancer. Hydroxydaunorubicin damages the cell’s DNA and may kill cancer cells. It also blocks a certain enzyme needed for cell division and DNA repair. Hydroxydaunorubicin is a type of anthracycline antibiotic and a type of topoisomerase inhibitor. Also called Adriamycin and doxorubicin hydrochloride.
hydroxymethylglutaryl-coenzyme A reductase inhibitor: (hy-DROK-see-MEH-thul-GLOO-tuh-ril-koh-EN-zime A ree-DUK-tays in-HIH-bih-ter); A substance that blocks an enzyme needed by the body to make cholesterol and lowers the amount of cholesterol in the blood. Hydroxymethylglutaryl-coenzyme A reductase inhibitor drugs are called statins. Also called HMG-CoA reductase inhibitor.
hydroxyurea: (hy-DROK-see-yoo-REE-uh); A drug used alone or with other anticancer drugs or radiation therapy under the brand name Hydrea to treat certain types of chronic myelogenous leukemia and head and neck cancer and under the brand name Droxia to treat certain patients with sickle cell anemia. It is also being studied in the treatment of other conditions and types of cancer. Hydroxyurea stops cells from making DNA and may kill cancer cells. It may also make cancer cells easier to kill with radiation therapy. Hydroxyurea may also help keep abnormal red blood cells from forming, which may reduce the number of painful sickle cell crises and the need for blood transfusions. Hydroxyurea is a type of antimetabolite.
hygiene: (HY-jeen); The science of health, and the practice of cleanliness that promotes good health and well-being.
hyper-CVAD: (HY-per ...); An abbreviation for a chemotherapy combination used to treat some types of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL). Hyper-CVAD includes the drugs cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride (Adriamycin), and dexamethasone. It also includes the drugs methotrexate and cytarabine. It is given as hyperfractionated therapy, in which the total dose of the drugs is divided into small doses and given more than once a day. Also called hyper-CVAD regimen.
hyper-CVAD regimen: (HY-per ... REH-jih-men); An abbreviation for a chemotherapy combination used to treat some types of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL). Hyper-CVAD regimen includes the drugs cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride (Adriamycin), and dexamethasone. It also includes the drugs methotrexate and cytarabine. It is given as hyperfractionated therapy, in which the total dose of the drugs is divided into small doses and given more than once a day. Also called hyper-CVAD.
hyperactivity: (HY-per-ak-TIH-vih-tee); A higher than normal level of activity. Hyperactivity can be used to describe the increased action of a body function, such as hormone production, or behavior. A person who is hyperactive may seem to be always moving or fidgeting, impulsive, unable to concentrate, and talking too much.
hyperalgesia: (HY-per-al-JEE-zee-uh); An increased sensitivity to feeling pain and an extreme response to pain. Hyperalgesia may occur when there is damage to the nerves or chemical changes to the nerve pathways involved in sensing pain. This may be caused by tissue injury or inflammation or by taking certain drugs, such as opioids, for chronic pain. People with hyperalgesia tend to feel extreme pain even though an injury or medical condition has not gotten worse. This pain may get worse over time, and it may extend to other areas of the body. It may also become a new or different type of pain than the original pain.
hyperalimentation: (HY-per-A-lih-men-TAY-shun); A form of nutritional support that is given directly into the bloodstream through a catheter placed into a vein. Hyperalimentation bypasses the digestive system and may be given when a person is not able to eat or drink by mouth or has a disease or condition that affects their ability to absorb nutrients through the digestive system. There are two types of hyperalimentation: partial parenteral nutrition (PPN) and total parenteral nutrition (TPN). PPN is supplemental nutrition that is given when a person cannot get enough calories or the right amount of nutrients that their body needs from the food they are eating. TPN is complete nutrition that provides all the calories, proteins, carbohydrates, fats, vitamins, and minerals that a person needs when they cannot digest food. Also called parenteral nutrition.
hyperbaric oxygen: (HY-per-BAYR-ik OK-sih-jen); Oxygen that is given at a pressure that is higher than the pressure of the atmosphere at sea level. In medicine, breathing hyperbaric oxygen increases the amount of oxygen in the body. It is used in treating certain kinds of wounds, injuries, and infections. It is also used to treat carbon monoxide poisoning and other conditions in which the tissues are not getting enough oxygen. It is being studied in the treatment of some types of cancer. Hyperbaric oxygen may increase the amount of oxygen in cancer cells, which may make them easier to kill with radiation therapy and chemotherapy. It is a type of radiosensitizing agent and a type of chemosensitizing agent.
hyperbilirubinemia: (HY-per-bih-lih-ROO-bih-NEE-mee-uh); Higher-than-normal amount of bilirubin in the blood. Bilirubin is a substance formed when red blood cells break down.
hypercalcemia: (HY-per-kal-SEE-mee-uh); Higher than normal levels of calcium in the blood. Some types of cancer increase the risk of hypercalcemia.
hypercortisolism: (HY-per-KOR-tih-SOL-ih-zum); A condition in which there is too much cortisol (a hormone made by the outer layer of the adrenal gland) in the body. Hypercortisolism may be caused by taking too many steroid drugs or by certain types of tumors. Tumors that make adrenocorticotropic hormone (ACTH) cause the adrenal gland to make too much cortisol. Symptoms of hypercortisolism include a round face, thin arms and legs, severe fatigue and muscle weakness, high blood pressure, high blood sugar, purple or pink stretch marks on the skin, and weight gain, especially in the abdomen. Also called Cushing syndrome.
hypercytokinemia: (HY-per-SY-toh-kih-NEE-mee-uh); A severe immune reaction in which the body releases too many cytokines into the blood too quickly. Cytokines play an important role in normal immune responses, but having a large amount of them released in the body all at once can be harmful. Hypercytokinemia can occur as a result of an infection, autoimmune condition, or other disease. It may also occur after treatment with some types of immunotherapy. Signs and symptoms include high fever, inflammation (redness and swelling), and severe fatigue and nausea. Sometimes, hypercytokinemia may be severe or life threatening and lead to multiple organ failure. Also called cytokine storm.
hyperdiploid: (HY-per-DIP-loyd); A term used to describe cells that have a higher-than-normal amount of DNA, such as having more than the usual number of chromosomes. Most human cells, except for egg and sperm cells, normally contain 46 chromosomes (23 pairs) in each cell. Some types of cancer cells, such as neuroblastoma cells or leukemia cells, may be hyperdiploid. Knowing whether cancer cells are hyperdiploid may help plan treatment and estimate prognosis.
hyperfractionated radiation therapy: (HY-per-FRAK-shuh-NAY-ted RAY-dee-AY-shun THAYR-uh-pee); Radiation treatment in which the total dose of radiation is divided into small doses and treatments are given more than once a day. Hyperfractionated radiation therapy is given over the same period of time (days or weeks) as standard radiation therapy. Also called superfractionated radiation therapy.
hyperfractionation: (HY-per-FRAK-shuh-NAY-shun); A treatment schedule in which the total dose of radiation or chemotherapy is divided into small doses and treatments are given more than once a day.
hyperglycemia: (HY-per-gly-SEE-mee-uh); Higher than normal amount of glucose (a type of sugar) in the blood. Hyperglycemia can be a sign of diabetes or other conditions. Also called high blood sugar.
Hypericum perforatum: (hy-PAYR-ih-kum per-fuh-RAY-tum); An herbal product sold as an over-the-counter treatment for depression. It is being studied for its ability to lessen certain side effects of cancer treatment. Also called St. John's wort.
hyperkeratosis: (HY-per-KAYR-uh-TOH-sis); A condition marked by thickening of the outer layer of the skin, which is made of keratin (a tough, protective protein). It can result from normal use (corns, calluses), chronic inflammation (eczema), or genetic disorders (X-linked ichthyosis, ichthyosis vulgaris).
hypernephroma: (HY-per-neh-FROH-muh); Cancer that begins in the lining of the tiny tubes in the kidney that return filtered substances that the body needs back to the blood and remove extra fluid and waste as urine. Hypernephroma is the most common type of kidney cancer in adults. Also called renal cell adenocarcinoma, renal cell cancer, and renal cell carcinoma.
hyperparathyroidism: (HY-per-PAYR-uh-THY-roy-dih-zum); A condition in which the parathyroid gland (one of four pea-sized organs found on the thyroid) makes too much parathyroid hormone. This causes a loss of calcium from the bones and an increased level of calcium in the blood. Symptoms include bone pain and kidney problems.
hyperpigmentation: (HY-per-pig-men-TAY-shun); A common, usually harmless condition in which patches of skin are darker than the surrounding skin. It occurs when special cells in the skin make too much of the pigment called melanin. Hyperpigmentation may appear as freckles, age spots, or larger areas of darkened skin. Hyperpigmentation may be caused by injury or inflammation of the skin, sun damage, abnormal skin growths, hormone changes, pregnancy, or other medical conditions. Certain medicines, including some anticancer drugs, can also cause hyperpigmentation.
hyperplasia: (HY-per-PLAY-zhuh); An increase in the number of cells in an organ or tissue. These cells appear normal under a microscope. They are not cancer, but may become cancer.
hypersensitivity: (HY-per-SEN-sih-tih-vih-tee); An exaggerated response by the immune system to a drug or other substance.
hypertension: (HY-per-TEN-shun); A blood pressure of 140/90 or higher. Hypertension usually has no symptoms. It can harm the arteries and cause an increase in the risk of stroke, heart attack, kidney failure, and blindness. Also called high blood pressure.
hyperthermia: (HY-per-THER-mee-uh); Abnormally high body temperature. This may be caused as part of treatment, by an infection, or by exposure to heat.
hyperthermia therapy: (HY-per-THER-mee-uh THAYR-uh-pee); A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs.
hyperthermic intraperitoneal chemotherapy: (HY-per-THER-mik IN-truh-PAYR-ih-toh-NEE-ul KEE-moh-THAYR-uh-pee); A treatment used during surgery in which a heated solution containing anticancer drugs is infused directly into the abdominal cavity through a thin tube. After removal of as much tumor tissue as possible with surgery, hyperthermic intraperitoneal chemotherapy is given to kill any remaining tumor cells. It is most often used to treat cancers that have spread to the peritoneum (the lining of the abdominal cavity). Also called CHPP, continuous hyperthermic peritoneal perfusion, and HIPEC.
hyperthermic perfusion: (HY-per-THER-mik per-FYOO-zhun); A procedure in which a warmed solution containing anticancer drugs is used to bathe, or is passed through the blood vessels of, the tissue or organ containing the tumor.
hyperthyroidism: (HY-per-THY-roy-dih-zum); A condition that occurs when the thyroid gland makes more thyroid hormones than the body needs. Thyroid hormones control the way the body uses energy and affect the body’s metabolism. Hyperthyroidism may be caused by an autoimmune disorder called Graves’ disease, benign lumps in the thyroid gland, and inflammation of the thyroid gland. It may also be caused by consuming too much iodine in the diet or by taking too much thyroid hormone medicine. Signs and symptoms include weight loss, fatigue, rapid or irregular heartbeat, sweating, diarrhea, nervousness, mood swings, shaky hands, trouble sleeping, trouble tolerating heat, muscle weakness, and a goiter (an enlarged thyroid gland that may cause the bottom of the neck to look swollen). Hyperthyroidism can usually be controlled with treatment. Also called overactive thyroid.
hyperuricemia: (HY-per-YOO-rih-SEE-mee-uh); A buildup of uric acid (a byproduct of metabolism) in the blood. Hyperuricemia is a side effect of some anticancer drugs.
hypervascular: (HY-per-VAS-kyoo-ler); Having a large number of blood vessels.
hypnosis: (hip-NOH-sis); A trance-like state in which a person becomes more aware and focused on particular thoughts, feelings, images, sensations, or behaviors. While under hypnosis, a person may feel calm, relaxed, and more open to suggestion. Hypnosis is usually done with the help of a specially trained therapist. It may be used to help relieve stress, anxiety, and pain, and to help a person quit smoking or lose weight. Hypnosis is a type of complementary and alternative medicine (CAM).
hypofractionated radiation therapy: (HY-poh-FRAK-shuh-NAY-ted RAY-dee-AY-shun THAYR-uh-pee); Radiation treatment in which the total dose of radiation is divided into large doses and treatments are given once a day or less often. Hypofractionated radiation therapy is given over a shorter period of time (fewer days or weeks) than standard radiation therapy.
hypofractionation: (HY-poh-FRAK-shuh-NAY-shun); A treatment schedule in which the total dose of radiation is divided into large doses and treatments are given once a day or less often.
hypogammaglobulinemia: (HY-poh-GA-muh-GLAH-byoo-lih-NEE-mee-uh); A condition in which the level of immunoglobulins (antibodies) in the blood is low and the risk of infection is high.
hypoglycemia: (HY-poh-gly-SEE-mee-uh); Abnormally low blood sugar.
hypohidrosis: (HY-poh-hih-DROH-sis); A rare condition in which the sweat glands make little or no sweat. It can affect the whole body or a small part of the body. Hypohidrosis may be caused by severe burns, radiation, infection, inflammation, or other injuries to the skin. It may also be caused by certain medicines and some conditions that affect the skin, nerves, connective tissue, or sweat glands. It may be inherited as part of a genetic condition or develop later in life. Also called anhidrosis.
hypomagnesemia: (HY-poh-MAG-neh-SEE-mee-uh); Lower-than-normal amount of magnesium in the blood.
hyponatremia: (HY-poh-nuh-TREE-mee-uh); Lower-than-normal amount of sodium in the blood.
hypopharyngeal cancer: (HY-poh-fuh-RIN-jee-ul KAN-ser); Cancer that forms in tissues of the hypopharynx (the bottom part of the throat). The most common type is squamous cell carcinoma (cancer that begins in flat cells lining the hypopharynx).
hypopharynx: (HY-poh-FAYR-inx); The bottom part of the throat. Cancer of the hypopharynx is also known as hypopharyngeal cancer.
hypophosphatemia: (HY-poh-FOS-fuh-TEE-mee-uh); Lower-than-normal amount of phosphorus in the blood.
hypopigmentation: (HY-poh-pig-men-TAY-shun); A condition in which the skin is lighter in color than normal. It occurs when special cells in the skin do not make enough of the pigment called melanin. Hypopigmentation can affect a small area of the skin or it can be widespread. It usually appears as lighter than normal colored patches on the skin or as areas on the skin that appear white. Hypopigmentation may be caused by injury, inflammation, or infection of the skin; some medical conditions; or certain medicines.
hypospadias: (HY-poh-SPAY-dee-us); A birth defect in which the opening of the urethra (the tube through which urine leaves the body) is not in its normal place. In males with hypospadias, the urethra opens on the underside of the penis or between the anus and the scrotum. In females with hypospadias, it opens into the vagina. Hypospadias is much more common in males than in females, and can be corrected by surgery. Children with hypospadias have an increased risk of developing Wilms tumor (a type of kidney cancer).
hypotension: (HY-poh-TEN-shun); Abnormally low blood pressure.
hypothalamus: (HY-poh-THA-luh-mus); The area of the brain that controls body temperature, hunger, and thirst.
hypothesis: (hy-PAH-theh-sis); A tentative proposal made to explain certain observations or facts that requires further investigation to be verified.
hypothyroidism: (HY-poh-THY-roy-dih-zum); Too little thyroid hormone. Symptoms include weight gain, constipation, dry skin, and sensitivity to the cold. Also called underactive thyroid.
hypotrichosis: (HY-poh-trih-KOH-sis); A rare condition in which there is little or no hair growth on the head, including the brows above the eyes and the edge of the eyelids, or other areas of the body where hair normally grows. Hair in the affected areas usually stays short and is dry and rough. It may also be tightly curled, lighter in color, and break easily. Hypotrichosis is usually congenital (present at birth) and is linked to several different genetic syndromes.
hypoxemia: (HY-pok-SEE-mee-uh); A condition in which there is not enough oxygen in the blood.
hypoxia: (hy-POK-see-uh); A condition in which there is a decrease in the oxygen supply to a tissue. In cancer treatment, the level of hypoxia in a tumor may help predict the response of the tumor to the treatment.
hypoxia-inducible factor: (hy-POK-see-uh-in-DOO-sih-bul FAK-ter); One of a group of proteins that play an important role in how cells respond to changing levels of oxygen. When oxygen levels in cells are low, hypoxia-inducible factors activate certain genes involved in cell growth and survival. This allows the cells to function and survive even in low oxygen conditions. Hypoxia-inducible factors may be made in larger than normal amounts by some types of cancer cells. This may cause cancer cells to grow and spread to other parts of the body. Also called HIF.
hypoxic: (hy-POK-sik); Having too little oxygen.
hysterectomy: (HIS-teh-REK-toh-mee); Surgery to remove the uterus, and sometimes surrounding organs and tissues. There are several different types of hysterectomy. When only the uterus is removed, it is called a partial hysterectomy. When the uterus and cervix are removed, it is called a total hysterectomy. When the uterus, cervix, part of the vagina, and a wide area of ligaments and tissues around these organs are removed, it is called a radical hysterectomy. These procedures may be done through the vagina (with no incisions in the abdomen) or through an incision (cut) in the abdomen.
Hytrin: (HY-trin); A drug used to treat urinary problems caused by an enlarged prostate. It is also used to treat high blood pressure and is being studied in the treatment of other conditions. Hytrin relaxes muscle tissue in blood vessels and in the prostate. It is a type of alpha blocker. Also called terazosin hydrochloride.