NCI Dictionary of Cancer Terms

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The NCI Dictionary of Cancer Terms features 7,777 terms related to cancer and medicine.

Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.

85 results found for: U
u-plasminogen activator
(u-plaz-MIH-noh-jen AK-tih-vay-ter)
An enzyme that is made in the kidney and found in the urine. A form of this enzyme is made in the laboratory and used to dissolve blood clots or to prevent them from forming. Also called uPA, urokinase, and urokinase-plasminogen activator.
ubiquinone
(yoo-BIH-kwih-NONE)
A nutrient that the body needs in small amounts to function and stay healthy. Ubiquinone helps mitochondria (small structures in the cell) make energy. It is an antioxidant that helps prevent cell damage caused by free radicals (highly reactive chemicals). Ubiquinone is fat-soluble (can dissolve in fats and oils) and is found in fatty fish, beef, soybeans, peanuts, and spinach. It is being studied in the prevention and treatment of some types of cancer and heart disease and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, CoQ10, Q10, and vitamin Q10.
UCN-01
An anticancer drug that belongs to the family of drugs called staurosporine analogs.
UFT
A substance being studied in the treatment of some types of cancer. It is a combination of tegafur and uracil. The tegafur is taken up by the cancer cells and breaks down into 5-FU, a substance that kills tumor cells. The uracil causes higher amounts of 5-FU to stay inside the cells and kill them. UFT is a type of antimetabolite. Also called Ftorafur and tegafur-uracil.
UGT1A1
A substance that is being studied as a treatment for cancer. It is an enzyme produced by the liver and intestine.
ulcer
(UL-ser)
A break on the skin, in the lining of an organ, or on the surface of a tissue. An ulcer forms when the surface cells become inflamed, die, and are shed. Ulcers may be linked to cancer and other diseases.
ulceration
(UL-seh-RAY-shun)
The formation of a break on the skin or on the surface of an organ. An ulcer forms when the surface cells die and are cast off. Ulcers may be associated with cancer and other diseases.
ulcerative colitis
(UL-seh-RUH-tiv koh-LY-tis)
Chronic inflammation of the colon that produces ulcers in its lining. This condition is marked by abdominal pain, cramps, and loose discharges of pus, blood, and mucus from the bowel.
Ulmus fulva
(UL-mus FUL-vuh)
The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called gray elm, Indian elm, red elm, slippery elm, sweet elm, and Ulmus rubra.
Ulmus rubra
(UL-mus ROO-bruh)
The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called gray elm, Indian elm, red elm, slippery elm, sweet elm, and Ulmus fulva.
ultra light cigarette
(UL-truh lite SIH-guh-ret)
A type of cigarette that is claimed to give off less tobacco tar than a regular or light (“low-tar”) cigarette when smoked. Ultra light cigarettes have been shown to be no safer than regular cigarettes, and smoking them does not lower the risk of cancer or other diseases. A person smoking an ultra light cigarette can inhale the same amount of tobacco tar, nicotine, and harmful, cancer-causing chemicals as in a regular cigarette, depending on how the cigarette is smoked. Cigarettes are no longer allowed to be labeled or advertised as ultra light cigarettes.
Ultram
(UL-tram)
A drug used to treat moderate to severe pain in adults. It binds to opioid receptors in the central nervous system. Ultram is a type of analgesic agent and a type of opioid. Also called tramadol hydrochloride.
ultrasonogram
(UL-truh-SAH-noh-gram)
A computer picture of areas inside the body created by high-energy sound waves. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of the body tissues on a computer screen. An ultrasonogram may be used to help diagnose disease, such as cancer. It may also be used during pregnancy to check the fetus (unborn baby) and during medical procedures, such as biopsies. Also called sonogram.
ultrasonography
(UL-truh-soh-NAH-gruh-fee)
A procedure that uses high-energy sound waves to look at tissues and organs inside the body. The sound waves make echoes that form pictures of the tissues and organs on a computer screen (sonogram). Ultrasonography may be used to help diagnose diseases, such as cancer. It may also be used during pregnancy to check the fetus (unborn baby) and during medical procedures, such as biopsies. Also called ultrasound.
ultrasound
(UL-truh-sownd)
A procedure that uses high-energy sound waves to look at tissues and organs inside the body. The sound waves make echoes that form pictures of the tissues and organs on a computer screen (sonogram). Ultrasound may be used to help diagnose diseases, such as cancer. It may also be used during pregnancy to check the fetus (unborn baby) and during medical procedures, such as biopsies. Also called ultrasonography.
ultrasound biomicroscopy
(UL-truh-sownd BY-oh-my-KROS-koh-pee)
A type of ultrasound eye exam that makes a more detailed image than regular ultrasound. High-energy sound waves are bounced off the inside of the eye and the echo patterns are shown on the screen of an ultrasound machine. This makes a picture called a sonogram.
ultrasound energy
(UL-truh-sownd EH-ner-jee)
A form of therapy being studied as an anticancer treatment. Intensified ultrasound energy can be directed at cancer cells to heat them and kill them.
ultrasound transducer
(UL-truh-sownd tranz-DOO-ser)
A device that produces sound waves that bounce off body tissues and make echoes. The transducer also receives the echoes and sends them to a computer that uses them to create a picture called a sonogram. Transducers (probes) come in different shapes and sizes for use in making pictures of different parts of the body. The transducer may be passed over the surface of the body or inserted into an opening such as the rectum or vagina.
ultrasound-guided biopsy
(UL-truh-sownd-GY-ded BY-op-see)
A biopsy procedure that uses an ultrasound imaging device to find an abnormal area of tissue and guide its removal for examination under a microscope.
ultraviolet A radiation
(UL-truh-VY-oh-let A RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. Ultraviolet A radiation also comes from sun lamps and tanning beds. Ultraviolet A radiation may cause premature aging of the skin and skin cancer. It may also cause problems with the eyes and the immune system. Skin specialists recommend that people use sunscreens that protect the skin from ultraviolet radiation. In medicine, ultraviolet A radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. Also called UVA radiation.
ultraviolet B radiation
(UL-truh-VY-oh-let B RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. Ultraviolet B radiation causes sunburn, darkening and thickening of the outer layer of the skin, and melanoma and other types of skin cancer. It may also cause problems with the eyes and the immune system. Skin specialists recommend that people use sunscreens that protect the skin from ultraviolet radiation. In medicine, ultraviolet B radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. Also called UVB radiation.
ultraviolet C radiation
(UL-truh-VY-oh-let C RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. Most ultraviolet C radiation from the sun is blocked from the Earth’s surface by the ozone layer. In medicine, ultraviolet C radiation may also come from special lamps or a laser and is used to kill germs or to help heal wounds. It is also used to treat certain skin conditions such as psoriasis, vitiligo, and skin nodules of cutaneous T-cell lymphoma Also called UVC radiation.
ultraviolet radiation
(UL-truh-VY-oh-let RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. Ultraviolet radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB. Ultraviolet radiation also comes from sun lamps and tanning beds. It can cause skin damage, premature aging, melanoma, and other types of skin cancer. It can also cause problems with the eyes and the immune system. Skin specialists recommend that people use sunscreens that protect the skin from both kinds of ultraviolet radiation. In medicine, ultraviolet radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. Also called UV radiation.
ultraviolet radiation therapy
(UL-truh-VY-oh-let RAY-dee-AY-shun THAYR-uh-pee)
A form of radiation used in the treatment of cancer.
umbilical cord blood
(um-BIH-lih-kul KORD blud)
Blood from the umbilical cord of a newborn baby. This blood contains high concentrations of stem cells (cells from which all blood cells develop).
umbilical cord blood transplantation
(um-BIH-lih-kul kord blud tranz-plan-TAY-shun)
The injection of umbilical cord blood to restore an individual's own blood production system suppressed by anticancer drugs, radiation therapy, or both. It is being studied in the treatment of cancer and severe blood disorders such as aplastic anemia. Cord blood contains high concentrations of stem cells (cells from which all blood cells develop).
uncontrolled study
(UN-kun-TROLD STUH-dee)
A clinical study that lacks a comparison (i.e., a control) group.
unconventional cancer treatments
(UN-kun-VEN-shuh-nul KAN-ser TREET-ments)
Approaches that use substances or methods of treating cancer that have not been shown to be effective by accepted scientific methods, such as carefully designed clinical trials.
underactive thyroid
(... THY-royd)
Too little thyroid hormone. Symptoms include weight gain, constipation, dry skin, and sensitivity to the cold. Also called hypothyroidism.
undescended testicles
(UN-deh-SEN-ded TES-tih-kuls)
A condition in which one or both testicles fail to move from the abdomen, where they develop before birth, into the scrotum. Undescended testicles may increase the risk for development of testicular cancer. Also called cryptorchidism.
undifferentiated
(un-DIH-feh-REN-shee-AY-ted)
A term used to describe cells or tissues that do not have specialized ("mature") structures or functions. Undifferentiated cancer cells often grow and spread quickly.
unguent
(UNG-gwent)
A substance used on the skin to soothe or heal wounds, burns, rashes, scrapes, or other skin problems. Also called ointment.
unilateral
(YOO-nih-LA-teh-rul)
Having to do with one side of the body.
unilateral salpingo-oophorectomy
(YOO-nih-LA-teh-rul sal-PIN-goh-oh-oh-foh-REK-toh-mee)
Surgery to remove the ovary and fallopian tube on one side of the body.
United States Preventive Services Task Force
(yoo-NY-ted stayts pree-VEN-tiv SER-vih-ses …)
A volunteer group of health experts who review published research and make recommendations about prevention health care methods such as screening tests, counseling, immunizations, and medicines. Before making a recommendation, the United States Preventive Services Task Force looks at the strength (scientific quality and correctness) of the evidence found in the research and the benefits and harms of each method being reviewed. Recommendations are made to help healthcare providers and patients decide whether a specific method is right for a patient’s needs. The recommendations may change as new research studies are published. Also called USPSTF.
Unituxin
(yoo-nih-TUK-sin)
A drug used with granulocyte-macrophage colony-stimulating factor (GM-CSF), aldesleukin (IL-2), and 13-cis-retinoic acid to treat high-risk neuroblastoma. It is used in children whose disease has improved with other anticancer treatment. Unituxin binds to a substance called GD2, which is found on some types of cancer cells. Unituxin may block GD2 and help the immune system kill cancer cells. It is a type of monoclonal antibody. Also called Ch14.18, dinutuximab, MOAB Ch14.18, and monoclonal antibody Ch14.18.
unresectable
(UN-ree-SEK-tuh-bul)
Unable to be removed with surgery.
unresectable gallbladder cancer
(UN-ree-SEK-tuh-bul GAWL-bla-der KAN-ser)
Cancer that has spread to the tissues around the gallbladder (such as the liver, stomach, pancreas, intestine, or lymph nodes in the area) and cannot be surgically removed.
unresected
(UN-ree-SEK-ted)
Describes an organ, tissue, or cancer that has not been either partly or completely removed by surgery.
unsealed internal radiation therapy
(...RAY-dee-AY-shun THAYR-uh-pee)
Radiation therapy given by injecting a radioactive substance into the bloodstream or a body cavity, or by swallowing it. This substance is not sealed in a container.
uPA
An enzyme that is made in the kidney and found in the urine. A form of this enzyme is made in the laboratory and used to dissolve blood clots or to prevent them from forming. Also called u-plasminogen activator, urokinase, and urokinase-plasminogen activator.
upper endoscopy
(UH-per en-DOS-koh-pee)
Examination of the inside of the stomach using an endoscope, passed through the mouth and esophagus. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called gastroscopy.
upper extremity
(UH-per ek-STREH-mih-tee)
The part of the body that includes the arm, wrist, and hand.
upper gastrointestinal series
(UH-per GAS-troh-in-TES-tih-nul SEER-eez)
A series of x-ray pictures of the esophagus, stomach, and duodenum (the first part of the small intestine). The x-ray pictures are taken after the patient drinks a liquid containing barium sulfate (a form of the silver-white metallic element barium). The barium sulfate coats and outlines the inner walls of the upper gastrointestinal tract so that they can be seen on the x-ray pictures. Also called upper GI series.
upper GI series
(UH-per ... SEER-eez)
A series of x-ray pictures of the esophagus, stomach, and duodenum (the first part of the small intestine). The x-ray pictures are taken after the patient drinks a liquid containing barium sulfate (a form of the silver-white metallic element barium). The barium sulfate coats and outlines the inner walls of the upper gastrointestinal tract so that they can be seen on the x-ray pictures. Also called upper gastrointestinal series.
upstaging
(up-STAY-jing)
In cancer, changing the stage used to describe a patient’s cancer from a lower stage (less extensive) to a higher stage (more extensive). Upstaging is based on the results of additional staging tests. It is important to know the stage of the disease in order to plan the best treatment.
urachus
(YOO-rah-kus)
A fibrous cord that connects the urinary bladder to the umbilicus (navel). The urachus is formed as the allantoic stalk during fetal development and lasts through life. Also called median umbilical ligament.
uracil
(YOOR-uh-sil)
A chemical compound that is used to make one of the building blocks of RNA. It is a type of pyrimidine.
urea
(yoo-REE-uh)
A substance formed by the breakdown of protein in the liver. The kidneys filter urea out of the blood and into the urine. Urea can also be made in the laboratory. A topical form of urea is being studied in the treatment of hand-foot syndrome (pain, swelling, numbness, tingling, or redness of the hands or feet that may occur as a side effect of certain anticancer drugs). Also called carbamide.
urea nitrogen
(yoo-REE-uh NY-troh-jen)
Nitrogen in the blood that comes from urea (a substance formed by the breakdown of protein in the liver). The kidneys filter urea out of the blood and into the urine. A high level of urea nitrogen in the blood may be a sign of a kidney problem. Also called blood urea nitrogen and BUN.
urea/lactic acid-based cream
(yoo-REE-uh LAK-tik A-sid …)
A substance being studied in the treatment of hand-foot syndrome (a condition caused by chemotherapy and marked by tingling, numbness, and red, peeling skin). Urea/lactic acid-based cream is a moisturizer that may help break down the hardened protein in dry, scaly skin and relieve these symptoms.
ureter
(YER-eh-ter)
The tube that carries urine from the kidney to the bladder.
ureteronephrectomy
(YER-eh-ter-oh-neh-FREK-toh-mee)
Surgery to remove a kidney and its ureter. Also called nephroureterectomy.
ureteroscopy
(YER-eh-ter-OS-koh-pee)
Examination of the inside of the kidney and ureter, using a ureteroscope. A ureteroscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. The ureteroscope is passed through the urethra into the bladder, ureter, and renal pelvis (part of the kidney that collects, holds, and drains urine).
urethra
(yoo-REE-thruh)
The tube through which urine leaves the body. It empties urine from the bladder.
urethral cancer
(yoo-REE-thrul KAN-ser)
A rare cancer that forms in tissues of the urethra (the tube through which urine empties the bladder and leaves the body). Types of urethral cancer include transitional cell carcinoma (cancer that begins in cells that can change shape and stretch without breaking apart), squamous cell carcinoma (cancer that begins in flat cells lining the urethra), and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids).
uric acid
(YOO-rik A-sid)
A waste product left over from normal chemical processes in the body and found in the urine and blood. Abnormal buildup of uric acid in the body may cause a condition called gout. Increased levels of uric acid in the blood and urine can be a side effect of chemotherapy or radiation therapy.
urinalysis
(YOOR-ih-NA-lih-sis)
A test that determines the content of the urine.
urinary
(YOOR-ih-NAYR-ee)
Having to do with urine or the organs of the body that produce and get rid of urine.
urinary diversion
(YOOR-ih-NAYR-ee dih-VER-zhun)
A surgical procedure to make a new way for urine to leave the body. It may involve redirecting urine into the colon, using catheters to drain the bladder, or making an opening in the abdomen and collecting urine in a bag outside the body.
urinary incontinence
(YOOR-ih-NAYR-ee in-KON-tih-nents)
Inability to hold urine in the bladder.
urinary tract
(YOOR-ih-NAYR-ee trakt)
The organs of the body that produce and discharge urine. These include the kidneys, ureters, bladder, and urethra.
urine
(YOOR-in)
Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.
urine culture
(YOOR-in KUL-cher)
A laboratory test to check for bacteria, yeast, or other microorganisms in the urine. Urine cultures can help identify the type of microorganism that is causing an infection. This helps determine the best treatment. They may be used to help diagnose urinary tract infections, such as bladder infections. They may also be done after treatment for a urinary tract infection to make sure the microorganism that caused the infection is gone.
urine cytology
(YOOR-in sy-TAH-loh-jee)
Tests performed on cells in urine to detect disease.
urokinase
(YOOR-oh-KY-nays)
An enzyme that is made in the kidney and found in the urine. A form of this enzyme is made in the laboratory and used to dissolve blood clots or to prevent them from forming. Also called u-plasminogen activator, uPA, and urokinase-plasminogen activator.
urokinase plasminogen activator (uPA)-derived peptide A6
(YOOR-oh-KY-nays plaz-MIH-noh-jen AK-tih-vay-ter … deh-RIVED PEP-tide …)
A substance being studied in the treatment of cancer. Urokinase plasminogen activator (uPA)-derived peptide A6 is a small piece of a protein called urokinase (an enzyme that dissolves blood clots or prevents them from forming). It is a type of antiangiogenesis agent and a type of antimetastatic agent. Also called A6.
urokinase-plasminogen activator
(YOOR-oh-KY-nays-plaz-MIH-noh-jen AK-tih-vay-ter)
An enzyme that is made in the kidney and found in the urine. A form of this enzyme is made in the laboratory and used to dissolve blood clots or to prevent them from forming. Also called u-plasminogen activator, uPA, and urokinase.
urologic oncologist
(YOOR-uh-LAH-jik on-KAH-loh-jist)
A doctor who specializes in treating cancers of the male and female urinary tract and the male reproductive organs.
urologist
(yoo-RAH-loh-jist)
A doctor who specializes in diseases of the urinary organs in females and the urinary and sex organs in males.
urostomy
(yoo-ROS-toh-mee)
An operation to create an opening from inside the body to the outside, making a new way to pass urine.
urothelium
(yoo-roh-THEE-lee-um)
The lining of the urinary tract, including the renal pelvis, ureters, bladder, and urethra.
ursodiol
(ur-soh-DY-ol)
A drug that is used to dissolve gallstones in people who can’t have surgery to remove them. It is also being studied in the prevention of colorectal cancer. Ursodiol belongs to the family of drugs called anticholelithics.
urticaria
(ER-tih-KAYR-ee-uh)
Itchy, raised red areas on the skin. Urticaria are caused by a reaction to certain foods, drugs, infections, or emotional stress. Also called hives.
USPSTF
A volunteer group of health experts who review published research and make recommendations about prevention health care methods such as screening tests, counseling, immunizations, and medicines. Before making a recommendation, the USPSTF looks at the strength (scientific quality and correctness) of the evidence found in the research and the benefits and harms of each method being reviewed. Recommendations are made to help healthcare providers and patients decide whether a specific method is right for a patient’s needs. The recommendations may change as new research studies are published. Also called United States Preventive Services Task Force.
uterine cancer
(YOO-teh-rin KAN-ser)
Cancer that forms in tissues of the uterus (the small, hollow, pear-shaped organ in a woman's pelvis in which a fetus develops). Two types of uterine cancer are endometrial cancer (cancer that begins in cells lining the uterus) and uterine sarcoma (a rare cancer that begins in muscle or other tissues in the uterus).
uterine sarcoma
(YOO-teh-rin sar-KOH-muh)
A rare type of uterine cancer that forms in muscle or other tissues of the uterus (the small, hollow, pear-shaped organ in a woman's pelvis in which a fetus develops). It usually occurs after menopause. The two main types are leiomyosarcoma (cancer that begins in smooth muscle cells) and endometrial stromal sarcoma (cancer that begins in connective tissue cells).
uterus
(YOO-teh-rus)
The hollow, pear-shaped organ in a woman's pelvis. The uterus is where a fetus (unborn baby) develops and grows. Also called womb.
UV radiation
(… RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. UV radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB. UV radiation also comes from sun lamps and tanning beds. It can cause skin damage, premature aging, melanoma, and other types of skin cancer. It can also cause problems with the eyes and the immune system. Skin specialists recommend that people use sunscreens that protect the skin from both kinds of UV radiation. In medicine, UV radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. Also called ultraviolet radiation.
UVA radiation
(… RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. UVA radiation also comes from sun lamps and tanning beds. UVA radiation may cause premature aging of the skin and skin cancer. It may also cause problems with the eyes and the immune system. Skin specialists recommend that people use sunscreens that protect the skin from ultraviolet radiation. In medicine, UVA radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. Also called ultraviolet A radiation.
UVB radiation
(… RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. UVB radiation causes sunburn, darkening and thickening of the outer layer of the skin, and melanoma and other types of skin cancer. It may also cause problems with the eyes and the immune system. Skin specialists recommend that people use sunscreens that protect the skin from ultraviolet radiation. In medicine, UVB radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. Also called ultraviolet B radiation.
UVC radiation
(… RAY-dee-AY-shun)
Invisible rays that are part of the energy that comes from the sun. Most UVC radiation from the sun is blocked from the Earth’s surface by the ozone layer. In medicine, UVC radiation may also come from special lamps or a laser and is used to kill germs or to help heal wounds. It is also used to treat certain skin conditions such as psoriasis, vitiligo, and skin nodules of cutaneous T-cell lymphoma Also called ultraviolet C radiation.
uvea
(YOO-vee-uh)
The middle layer of the wall of the eye. The uvea has 3 main parts: (1) the choroid (the tissue layer filled with blood vessels); (2) the ciliary body (the ring of muscle tissue that changes the size of the pupil and the shape of the lens); and (3) the iris (the colored part of the eye). Also called uveal tract.
uveal tract
(YOO-vee-ul trakt)
The middle layer of the wall of the eye. The uveal tract has 3 main parts: (1) the choroid (the tissue layer filled with blood vessels); (2) the ciliary body (the ring of muscle tissue that changes the size of the pupil and the shape of the lens); and (3) the iris (the colored part of the eye). Also called uvea.
uvula
(YOO-vyoo-luh)
The soft flap of tissue that hangs down at the back of the mouth (at the edge of the soft palate). Also called palatine uvula.