1. What are vaccines?

Vaccines are medicines that boost the immune system’s natural ability to protect the body against “foreign invaders” that may cause disease. These invaders are primarily microbes, which can be seen only under a microscope. Microbes include bacteria, viruses, parasites, and fungi.

The immune system is a complex network of organs, tissues, and specialized cells that act collectively to defend the body. When a particular type of microbe invades the body, the immune system recognizes it as foreign, destroys it, and “remembers” it to prevent another infection. Vaccines take advantage of this response.

Traditional vaccines usually contain harmless versions of microbes—killed or weakened microbes, or parts of microbes—that do not cause disease but are able to stimulate an immune response. When the immune system encounters these substances through vaccination, it responds to them, eliminates them from the body, and develops a memory of them. This vaccine-induced memory enables the immune system to act quickly to protect the body if it becomes infected by the same microbe in the future.

The immune system’s role in defending against disease-causing microbes has long been recognized. Scientists have also discovered that the immune system can protect the body against threats posed by certain types of damaged, diseased, or abnormal cells, including cancer cells (1).

2. How do vaccines stimulate the immune system?

White blood cells, or leukocytes, play the main role in immune responses. These cells carry out the many tasks required to protect the body against disease-causing microbes and abnormal cells.

Some types of leukocytes patrol the body, seeking foreign invaders and diseased, damaged, or dead cells. These white blood cells provide a general—or nonspecific—level of immune protection.

Other types of leukocytes, known as lymphocytes, provide targeted protection against specific threats, whether from a specific microbe or a diseased or abnormal cell. The most important groups of lymphocytes responsible for carrying out immune responses against such threats are B cells and cytotoxic (cell-killing) T cells.

B cells make antibodies, which are large proteins secreted by B cells that bind to, inactivate, and help destroy foreign invaders or abnormal cells. Most preventive vaccines, including those aimed at hepatitis B virus (HBV) and human papillomavirus (HPV), stimulate the production of antibodies that bind to specific, targeted microbes and block their ability to cause infection. Cytotoxic T cells, which are also known as killer T cells, kill infected or abnormal cells by releasing toxic chemicals or by prompting the cells to self-destruct (apoptosis).

Other types of lymphocytes and leukocytes play supporting roles to ensure that B cells and killer T cells do their jobs effectively. Cells that help fine-tune the activities of B cells and killer T cells include helper T cells and dendritic cells, which help activate killer T cells and enable them to recognize specific threats.

Cancer treatment vaccines work by activating B cells and killer T cells and directing them to recognize and act against specific types of cancer. They do this by introducing one or more molecules known as antigens into the body, usually by injection. An antigen is a substance that stimulates a specific immune response. An antigen can be a protein or another type of molecule found on the surface of or inside a cell.

Microbes carry antigens that “tell” the immune system they are foreign—or
“non-self”—and, therefore, represent a potential threat that should be destroyed. In contrast, normal cells in the body have antigens that identify them as “self.” Self antigens tell the immune system that normal cells are not a threat and should be ignored (2).

Cancer cells can carry both types of antigens. They have self antigens, which they share in common with normal cells, but they may also have antigens that are unique to cancer cells. These cancer-associated antigens mark cancer cells as abnormal, or non-self, and can cause B cells and killer T cells to mount an attack against the cancer.

Cancer cells may also make much larger than normal amounts of certain self antigens. These overly abundant self antigens may be viewed by the immune system as being foreign and, therefore, may trigger an immune response against the cancer (1–6).

3. What are cancer vaccines?

Cancer vaccines are medicines that belong to a class of substances known as biological response modifiers. Biological response modifiers work by stimulating or restoring the immune system’s ability to fight infections and disease. There are two broad types of cancer vaccines:

• Preventive (or prophylactic) vaccines, which are intended to prevent cancer from developing in healthy people; and
• Treatment (or therapeutic) vaccines, which are intended to treat already existing cancers by strengthening the body's natural defenses against cancer (7).

Two types of cancer preventive vaccines have been successfully developed and are available in the United States (see Question 5). However, cancer treatment vaccines remain an experimental form of therapy.

4. How do cancer preventive vaccines work?

Cancer preventive vaccines target infectious agents that cause or contribute to the development of cancer (8). They are similar to traditional vaccines, which help prevent infectious diseases such as measles or polio by protecting the body against infection. Both cancer preventive vaccines and traditional vaccines are based on antigens that are carried by the infectious agents and that are relatively easy for the immune system to recognize as foreign.

5. Have any cancer preventive vaccines been approved for use in the United States?

In 2006, the U.S. Food and Drug Administration (FDA) approved the vaccine known as Gardasil®, which protects against infection by two types of HPV—specifically, types 16 and 18—that cause approximately 70 percent of all cases of cervical cancer worldwide. At least 17 other types of HPV are responsible for the remaining 30 percent of cervical cancer cases (9). Gardasil also protects against HPV types 6 and 11, which are responsible for about 90 percent of all cases of genital warts. However, these two HPV types do not cause cervical cancer.

In 2008, the FDA expanded Gardasil’s approval to include its use in the prevention of HPV-associated vulvar and vaginal cancers.

Gardasil, manufactured by Merck & Company, is based on HPV antigens that are proteins. These proteins are used in the laboratory to make four different types of “virus-like particles,” or VLPs, which correspond to HPV types 6, 11, 16, and 18. The four types of VLPs are then combined to make the vaccine. Because Gardasil targets four HPV types, it is called a quadrivalent vaccine (10). In contrast with traditional vaccines, which are often composed of weakened, whole microbes, the VLPs in Gardasil are not infectious. However, they are still able to stimulate the production of antibodies against HPV types 6, 11, 16, and 18.

A second HPV vaccine manufactured by GlaxoSmithKline and known by the name Cervarix® has also been developed. Although Cervarix has been approved for use in Europe, it has not yet been approved by the FDA for use in the United States. In contrast with Gardasil, Cervarix is a bivalent vaccine. It is composed of VLPs made with proteins from HPV types 16 and 18. Therefore, it provides protection only against these two HPV types.

The public health benefits of vaccines against HPV types 16 and 18 may extend beyond reducing the risks of cervical cancer, vaginal cancer, and vulvar cancer. Evidence suggests that chronic infection by one or both of these virus types is also associated with cancers of the anus, penis, and oropharynx (11).

The FDA has approved one other type of cancer preventive vaccine, which protects against HBV infection. Chronic HBV infection can lead to liver cancer. The first HBV vaccine was approved in 1981, making it the first cancer preventive vaccine to be successfully developed and marketed. Today, most children in the United States are vaccinated against HBV shortly after birth (12).

6. Have other microbes been associated with cancer?

Many scientists believe that microbes cause or contribute to between 15 percent and 25 percent of all cancers diagnosed worldwide each year, with the percentages being lower in developed countries than in developing countries (4, 8, 13, 14). The International Agency for Research on Cancer (IARC) has classified several microbes as carcinogenic (causing or contributing to the development of cancer in people), including HPV and HBV (15). These infectious agents—bacteria, viruses, and parasites—and the cancer types with which they are most strongly associated are listed in the table below.

Infectious Agents	Type of Organism	Associated Cancer(s)
hepatitis B virus (HBV)	virus	hepatocellular carcinoma (a type of liver cancer)
hepatitis C virus (HCV)	virus	hepatocellular carcinoma (a type of liver cancer)
human papillomavirus (HPV) types 16 and 18, as well as other HPV types	virus	cervical cancer; vaginal cancer; vulvar cancer; oropharyngeal cancer (cancers of the base of the tongue, tonsils, or upper throat); anal cancer; penile cancer
Epstein-Barr virus	virus	Burkitt lymphoma; non-Hodgkin lymphoma; Hodgkin lymphoma; nasopharyngeal carcinoma (cancer of the upper part of the throat behind the nose)
human T-cell lymphotropic virus 1 (HTLV1)	virus	acute T-cell leukemia
Helicobacter pylori	bacterium	stomach cancer
schistosomes (Schistosoma hematobium)	parasite	bladder cancer
liver flukes (Opisthorchis viverrini)	parasite	cholangiocarcinoma (a type of liver cancer)




7. How do cancer treatment vaccines work?

Cancer treatment vaccines are designed to treat cancers that have already occurred. They are intended to delay or stop cancer cell growth; cause tumor shrinkage; prevent cancer from coming back; or eliminate cancer cells that are not killed by other forms of treatment, such as surgery, radiation therapy, or chemotherapy.

Developing effective cancer treatment vaccines requires a detailed understanding of how immune system cells and cancer cells interact. The immune system often does not “see” cancer cells as dangerous or foreign, as it generally does with microbes. Therefore, the immune system does not mount a strong attack against the cancer cells.

There are many reasons the immune system does not easily recognize the threat posed by an already growing cancer. Most important is the fact that cancer cells carry normal self antigens in addition to any cancer-associated antigens. Furthermore, cancer cells sometimes undergo genetic changes that lead to the loss of cancer-associated antigens. Finally, cancer cells can produce chemical messages that suppress specific anticancer immune responses by killer T cells. As a result, even when the immune system recognizes a growing cancer as a threat, the cancer may still escape a strong attack by the immune system (16).

8. Has the FDA approved any cancer treatment vaccines?

The FDA has not approved any type of cancer treatment vaccine. Producing effective treatment vaccines has proved much more difficult and challenging than developing cancer preventive vaccines (17).

To be effective, cancer treatment vaccines must achieve two goals. First, similar to traditional vaccines and cancer preventive vaccines, cancer treatment vaccines must stimulate specific immune responses and direct them against the correct target. Second, the immune responses stimulated by cancer treatment vaccines must be powerful enough to overcome the barriers that cancer cells use to protect themselves from attack by B cells and killer T cells. Recent advances in understanding how cancer cells escape recognition and attack by the immune system are now giving researchers the knowledge required to design cancer treatment vaccines that can accomplish both goals (18, 19).

9. What types of vaccines are being studied in clinical trials?

Vaccines to prevent HPV infection and to treat several types of cancer are being studied in clinical trials.

The list below shows the types of cancer that are being targeted in active cancer prevention or treatment clinical trials using vaccines. In the HTML version of this fact sheet on the Web site (http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines), the cancer names are links to search results for cancer vaccine trials in the National Cancer Institute’s (NCI) clinical trials database. This database can also be searched on NCI’s Web site, http://www.cancer.gov, by visiting http://www.cancer.gov/clinicaltrials/search on the Internet.

Active Clinical Trials of Cancer Treatment Vaccines by Type of Cancer:

• Bladder Cancer ¹
• Brain Tumors ²
• Breast Cancer ³
• Cervical Cancer ⁴
• Kidney Cancer ⁵
• Melanoma ⁶
• Multiple Myeloma ⁷
• Leukemia ⁸
• Lung Cancer ⁹
• Pancreatic Cancer ¹⁰
• Prostate Cancer ¹¹
• Solid Tumors ¹²

Active Clinical Trials of Cancer Preventive Vaccines by Type of Cancer:

• Cervical Cancer ¹³

10. How are cancer vaccines made, and what antigens are used?

Scientists make cancer preventive vaccines using antigens from microbes that cause or contribute to the development of cancer. The cancer preventive vaccines currently approved by the FDA are made using antigens from HBV and specific types of HPV (see Question 5). These antigens are proteins that help make up the outer surface of the viruses. Because only part of these microbes is used, the resulting vaccines are not infectious and, therefore, cannot cause disease.

Researchers can also create synthetic versions of antigens in the laboratory for use in vaccines. In doing this, they often modify the chemical structure of the antigens to stimulate immune responses that are stronger than those caused by the original antigens.

Similar to cancer preventive vaccines, cancer treatment vaccines can be made using antigens from cancer cells—either directly or by making modified versions of them. Antigens that have been used thus far include proteins; carbohydrates (sugars); glycoproteins or glycopeptides, which are carbohydrate-protein combinations; and gangliosides, which are carbohydrate-lipid (fat) combinations.

Cancer treatment vaccines can also be made using weakened or killed cancer cells that carry a specific cancer-associated antigen. These cells can be from a patient’s own cancer (called an autologous vaccine) or from another person’s cancer (called an allogeneic vaccine).

Other types of cancer treatment vaccines can be made using molecules of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) that contain the genetic instructions for cancer-associated antigens. The DNA or RNA can be injected alone into a patient as a “naked nucleic acid” vaccine, or researchers can insert the DNA or RNA into a harmless virus. After the naked nucleic acid or virus is injected into the body, the DNA or RNA is taken up by cells, which begin to manufacture the tumor-associated antigens. Researchers hope that the cells will make enough of the tumor-associated antigens to stimulate a strong immune response.

Scientists have identified a large number of cancer-associated antigens, several of which are now being used to make experimental cancer treatment vaccines. Some of these antigens are found on or in many or most types of cancer cells. Others are unique to specific cancer types (1, 5, 6, 20–25).

Antigens associated with more than one type of cancer include the following:

• Carcinoembryonic antigen (CEA): A glycoprotein found in developing fetal tissues and in certain types of cancer, including colorectal cancer, stomach cancer, pancreatic cancer, breast cancer, and non-small cell lung cancer.
• Cancer/testis antigens, such as NY-ESO-1: A large family of proteins found in male germ cells (sperm) and a wide variety of cancer types, including melanoma and cancers of the ovary, tongue, pharynx, brain, lung, colon, and breast.
• Mucin-1 (MUC1): A glycoprotein found in the outer membrane of mucus-producing epithelial cells (cells that make up the skin and line internal organs) and many types of cancer cells, including breast, prostate, colon, pancreatic, and non-small cell lung cancer cells. Sialyl Tn (STn) is a carbohydrate antigen related to mucin-1 that is being used in some treatment vaccines.
• Gangliosides, such as GM3 and GD2: Molecules that are found in the outer membrane of several types of cancer cells, including melanoma, neuroblastoma, small cell lung cancer, and soft tissue sarcomas.
• p53 protein: A protein produced by the tumor suppressor gene TP53. Mutation of TP53, which results in a loss of p53 protein function, is the most common abnormality in human cancer. Mutant p53 protein often accumulates in cancer cells, which makes p53 an attractive target for a vaccine.
• HER2/neu protein (also known as ERBB2): A protein that is overexpressed—or overproduced—in breast, ovarian, and several other types of cancer. Overexpression of HER2/neu is associated with more aggressive disease and a worse outcome. Targeting HER2/neu with a monoclonal antibody called trastuzumab (Herceptin®) has proven to be an effective treatment for breast cancers that overexpress this protein.

Antigens unique to a specific type of cancer include the following:

• A mutant form of the epidermal growth factor receptor, called EGFRvIII: An abnormal protein that contributes to uncontrolled tumor growth and is found in glioblastoma (a type of brain cancer), but not in normal brain tissue.
• Melanocyte/melanoma differentiation antigens, such as tyrosinase, MART1, and gp100: Proteins found in mature melanocytes (pigment-producing cells of the skin and eye) and in melanoma cells.
• Prostate-specific antigen (PSA): A protein that is often produced in much greater amounts by prostate cancer cells than by normal prostate cells.
• Idiotype (Id) antibodies: Antibodies produced by cancerous B cells that serve as antigen markers for diseases such as multiple myeloma and several types of lymphoma. Id antibodies are unique to an individual patient's cancer.


11. Are other substances used to make cancer treatment vaccines?

Yes. Researchers can use certain immune system cells and their products, as well as antibodies created in the laboratory, to make cancer treatment vaccines.

Some examples include the following:

• Dendritic Cells and Costimulatory Molecules: Scientists can use a type of white blood cell known as a dendritic cell to make cancer treatment vaccines. Dendritic cells are powerful stimulators of immune responses. They process and present cancer-associated antigens to T cells and B cells, and they produce costimulatory molecules that enhance the cell-killing properties of killer T cells (1, 2, 23–26).

  To make autologous dendritic-cell vaccines, researchers often harvest dendritic cells from the blood of a cancer patient and grow the cells in the laboratory while “feeding” them cancer-associated antigens. Dendritic cells can be fed antigens directly, or they can be exposed to DNA, RNA, or viruses that contain the genetic instructions for the antigens. After taking up the DNA, RNA, or virus genetic material, the dendritic cells manufacture and process the antigens for display on their cell surface to other immune system cells. Researchers then inject these “antigen-presenting cells” into the patient’s bloodstream. In the body, the dendritic cells interact with killer T cells and other immune system cells to generate anticancer immune responses.

  Researchers can also create synthetic versions of the costimulatory molecules produced by dendritic cells and add them to other types of treatment vaccines to strengthen killer-T-cell responses. Costimulatory molecules that are frequently used in treatment vaccines include ICAM–1, B7.1, and LFA–3. When used together in a vaccine, these three molecules are designated by the abbreviation TRICOM (22, 27).

• Idiotype (Id) Vaccines: Normal B cells and cancerous B cells, such as those produced in multiple myeloma and several types of lymphoma, each make only one type of antibody. In a patient with a B cell cancer, these unique antibodies, also called idiotype (Id) antibodies, can serve as antigen markers for the patient’s disease. Id antibodies can also be used to create personalized, autologous vaccines (28). When injected into a patient in large amounts, Id antibodies may be able to stimulate an immune response that will target cancerous B cells for destruction.

  Autologous Id vaccines typically include other substances called adjuvants, which increase the potency of immune responses (see Question 12). Id antibodies can also be used as antigens in making autologous dendritic-cell vaccines.

• Anti-Idiotype (Anti-Id) Monoclonal Antibody Vaccines: Monoclonal antibodies are substances created in the laboratory; each type of monoclonal antibody targets one specific antigen. Anti-Id antibodies have been developed that mimic antigens found on several types of cancer cells. These antibodies can trigger immune responses against cancer cells that bear the antigens that the anti-Id antibodies mimic.

  Cancer types for which anti-Id monoclonal antibodies have been developed include melanoma, breast cancer, small cell lung cancer, colorectal cancer, ovarian cancer, peritoneal cancer, and cancer of the fallopian tube.

12. What are adjuvants, and how are they used in making cancer vaccines?

Antigens and the substances discussed in Question 10 are often not enough to make effective cancer treatment vaccines. Researchers often add extra ingredients, known as adjuvants, to treatment vaccines. These substances serve to boost immune responses that have been set in motion by exposure to antigens or other means. Patients undergoing treatment with a cancer vaccine sometimes receive adjuvants separately from the vaccine itself (29).

Adjuvants used for cancer vaccines come from many different sources. Some microbes, such as the bacterium bacillus Calmette-Guérin (BCG) originally used as a vaccine against tuberculosis, can serve as adjuvants (30). Substances produced by bacteria, such as Detox B, are frequently used. Biological products derived from nonmicrobial organisms can also be used as adjuvants. One example is keyhole limpet hemocyanin (KLH), which is a large protein produced by a sea animal. Attaching antigens to KLH has been shown to increase their ability to stimulate immune responses. Even some nonbiological substances, such as the emulsified oil montanide ISA–51, can be used as adjuvants.

Scientists can also use natural or synthetic cytokines as adjuvants. Cytokines are substances that are naturally produced by white blood cells to regulate and fine-tune immune responses. Some cytokines increase the activity of B cells and killer T cells, while other cytokines suppress the activities of these cells. Cytokines frequently used in cancer treatment vaccines or given with them include interleukin 2 (IL2, also known as aldesleukin), interferon alpha (INF–a), and granulocyte-macrophage colony-stimulating factor (GM–CSF, also known as sargramostim).

13. What side effects have been seen with cancer vaccines?

Vaccines intended to prevent or treat cancer appear to have safety profiles comparable to those of traditional vaccines (6). However, the side effects of cancer vaccines can vary widely from one vaccine formulation to another and from one person to another.

The most commonly reported side effect of cancer vaccines is inflammation at the site where the vaccine is injected into the body. Reported symptoms include redness, pain, swelling, heightened temperature (the skin surrounding the injection site feels hot to the touch), itchiness, and occasionally a rash.

People sometimes experience flulike symptoms after receiving a cancer vaccine, including fever, chills, weakness, dizziness, nausea or vomiting, muscle ache, fatigue, headache, and occasional breathing difficulties. Blood pressure may also be affected.

Other, more serious health problems have been reported in smaller numbers of people after receiving a cancer vaccine. These problems may or may not have been caused by the vaccine. The reported problems have included asthma, appendicitis, pelvic inflammatory disease, and certain autoimmune diseases, including arthritis and systemic lupus erythematosus.

Vaccines, like any other medication affecting the immune system, can cause adverse effects that may prove life threatening. For example, severe hypersensitivity (allergic) reactions to specific vaccine ingredients have occurred following vaccination. However, such severe reactions are quite rare.

14. Can cancer treatment vaccines be combined with other types of cancer therapy?

Yes. In many of the clinical trials of cancer treatment vaccines that are now under way, vaccines are being administered with other forms of cancer therapy. Therapies that have been combined with cancer treatment vaccines include surgery, chemotherapy, radiation therapy, and some forms of targeted therapy, including therapies based on boosting immune system responses against cancer with biological response modifiers.

Several studies have suggested that cancer treatment vaccines may be most effective when given in combination with other forms of cancer therapy (24, 31). In addition, in some clinical trials, cancer treatment vaccines have appeared to increase the effectiveness of other cancer therapies (24, 31).

Additional evidence suggests that surgical removal of large tumor masses may enhance the effectiveness of cancer treatment vaccines (31). In patients with extensive disease, the immune system may be overwhelmed by the cancer and effective immune responses cannot be achieved. Surgical removal of the tumor may make it easier for the body to develop an immune response.

Researchers are also designing clinical trials to answer questions such as whether a specific cancer treatment vaccine works best when it is administered before chemotherapy, after chemotherapy, or at the same time as chemotherapy. Answers to such questions may not only provide information about how best to use a specific cancer treatment vaccine but also reveal additional basic principles to guide the future development of combination therapies involving vaccines.

15. What additional research is under way?

Although researchers have identified many cancer-associated antigens, these molecules vary widely in their capacity to stimulate a strong anticancer immune response. Two major areas of research aimed at developing better cancer treatment vaccines involve the discovery of new cancer-associated antigens that may prove more effective in stimulating immune responses than the already known antigens and the development of new methods to enhance the ability of cancer-associated antigens to stimulate the immune system. Research is also under way to determine how to combine multiple antigens within a single cancer treatment vaccine to produce optimal anticancer immune responses (22).

As mentioned in Question 14, another area of study is how best to combine cancer treatment vaccines with other types of anticancer therapy, whether surgery, chemotherapy, radiation therapy, targeted therapy, or other types of immune system therapy, including adoptive cell transfer (4, 17, 32–35). In adoptive cell transfer, which is also known as cellular adoptive immunotherapy, researchers harvest killer T cells that have anticancer activity from a patient’s tumor and, in the laboratory, both stimulate their growth to greatly increase their numbers and treat them to enhance their tumor-killing activity. The T cells are then injected into the patient (32–35).

Perhaps the most promising avenue of cancer vaccine research is aimed at better understanding the basic biology underlying how immune system cells and cancer cells interact. New technologies are being created as part of this effort. For example, a group of scientists recently developed a new type of imaging technology that allows researchers to observe killer T cells and cancer cells interacting on a one-to-one basis inside the body (36).

In addition, researchers are trying to identify the mechanisms by which cancer cells evade or suppress anticancer immune responses. A better understanding of how cancer cells manipulate the immune system could lead to the development of new drugs that block those processes and thereby improve the effectiveness of cancer treatment vaccines (27). For example, research has shown that some cancer cells produce chemical signals that attract white blood cells known as regulatory T cells, or Tregs, to a tumor site. Tregs produce cytokines that can either stimulate or suppress the activity of killer T cells. When Tregs move close to a tumor, they often release cytokines that suppress the activity of nearby killer T cells (24, 37). The combination of a cancer treatment vaccine with a drug that would block the negative effects of one or more of these suppressive cytokines on killer T cells might improve the vaccine’s effectiveness in generating potent killer T cell antitumor responses.

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# # #

• National Cancer Institute Fact Sheet 4.21, Human Papillomavirus (HPV) Vaccines: Questions and Answers ¹⁴
  (http://www.cancer.gov/cancertopics/factsheet/Prevention/HPV-vaccine)
• National Cancer Institute Fact Sheet 7.2, Biological Therapies for Cancer: Questions and Answers ¹⁵
  (http://www.cancer.gov/cancertopics/factsheet/Therapy/biological)
• Taking Part in Cancer Treatment Research Studies ¹⁶
  (http://www.cancer.gov/clinicaltrials/Taking-Part-in-Cancer-Treatment-Research-Studies)
• Understanding Cancer Series: The Immune System ¹⁷
  (http://www.cancer.gov/cancertopics/understandingcancer/immunesystem)
• Understanding Cancer Series: HPV Vaccine ¹⁸
  (http://www.cancer.gov/cancertopics/understandingcancer/HPV-vaccine)

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Glossary Terms

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

An unexpected medical problem that happens during treatment with a drug or other therapy. Adverse effects do not have to be caused by the drug or therapy, and they may be mild, moderate, or severe. Also called adverse event.

A quickly growing cancer.

A drug used to treat some types of cancer. It is a form of interleukin-2, a cytokine made by leukocytes (white blood cells), that is made in the laboratory. Aldesleukin increases the activity and growth of white blood cells called T lymphocytes and B lymphocytes. It is a type of biological response modifier. Also called Proleukin and recombinant human interleukin-2.

Taken from different individuals of the same species. Also called allogenic.

Cancer that forms in tissues of the anus. The anus is the opening of the rectum (last part of the large intestine) to the outside of the body.

A protein made by plasma cells (a type of white blood cell) in response to an antigen (a substance that causes the body to make a specific immune response). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

Any substance that causes the body to make a specific immune response.

A type of cell death in which a series of molecular steps in a cell leads to its death. This is the body’s normal way of getting rid of unneeded or abnormal cells. The process of apoptosis may be blocked in cancer cells. Also called programmed cell death.

A disease that causes inflammation and pain in the joints.

A chronic disease in which the bronchial airways in the lungs become narrowed and swollen, making it difficult to breathe. Symptoms include wheezing, coughing, tightness in the chest, shortness of breath, and rapid breathing. An attack may be brought on by pet hair, dust, smoke, pollen, mold, exercise, cold air, or stress.

A condition in which the body recognizes its own tissues as foreign and directs an immune response against them.

Taken from an individual's own tissues, cells, or DNA.

A type of immune cell that makes proteins called antibodies, which bind to microorganisms and other foreign substances, and help fight infections. A B cell is a type of white blood cell. Also called B lymphocyte.

A large group of single-cell microorganisms. Some cause infections and disease in animals and humans. The singular of bacteria is bacterium.

A weakened form of the bacterium Mycobacterium bovis (bacillus Calmette-Guérin) that does not cause disease. BCG is used in a solution to stimulate the immune system in the treatment of bladder cancer and as a vaccine to prevent tuberculosis. Also called bacillus Calmette-Guérin.

Pertaining to biology or to life and living things. In medicine, refers to a substance made from a living organism or its products. Biologicals may be used to prevent, diagnose, treat or relieve of symptoms of a disease. For example, antibodies, interleukins, and vaccines are biologicals. Biological also refers to parents and children who are related by blood.

Treatment to boost or restore the ability of the immune system to fight cancer, infections, and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Agents used in biological response modifier therapy include monoclonal antibodies, growth factors, and vaccines. These agents may also have a direct antitumor effect. Also called biological therapy, biotherapy, BRM therapy, and immunotherapy.

Cancer that forms in tissues of the bladder (the organ that stores urine). Most bladder cancers are transitional cell carcinomas (cancer that begins in cells that normally make up the inner lining of the bladder). Other types include squamous cell carcinoma (cancer that begins in thin, flat cells) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). The cells that form squamous cell carcinoma and adenocarcinoma develop in the inner lining of the bladder as a result of chronic irritation and inflammation.

The force of circulating blood on the walls of the arteries. Blood pressure is taken using two measurements: systolic (measured when the heart beats, when blood pressure is at its highest) and diastolic (measured between heart beats, when blood pressure is at its lowest). Blood pressure is written with the systolic blood pressure first, followed by the diastolic blood pressure (for example 120/80).

An aggressive (fast-growing) type of B-cell non-Hodgkin lymphoma that occurs most often in children and young adults. The disease may affect the jaw, central nervous system, bowel, kidneys, ovaries, or other organs. There are three main types of Burkitt lymphoma (sporadic, endemic, and immunodeficiency related). Sporadic Burkitt lymphoma occurs throughout the world, and endemic Burkitt lymphoma occurs in Africa. Immunodeficiency-related Burkitt lymphoma is most often seen in AIDS patients.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

A vaccine designed to prevent or treat cancer.

A sugar molecule. Carbohydrates can be small and simple (for example, glucose) or they can be large and complex (for example, polysaccharides such as starch, chitin or cellulose).

A substance that is sometimes found in an increased amount in the blood of people who have certain cancers, other diseases, or who smoke. It is used as a tumor marker for colorectal cancer. Also called CEA.

Cancer that begins in the skin or in tissues that line or cover internal organs.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

A treatment used to help the immune system fight cancer. A cancer patient’s T cells (a type of white blood cell) are collected and grown in the laboratory to increase the number of T cells that are able to kill the person’s cancer cells. These cancer-specific T cells are given back to the patient to help the immune system fight the cancer.

Cancer that forms in tissues of the cervix (the organ connecting the uterus and vagina). It is usually a slow-growing cancer that may not have symptoms but can be found with regular Pap tests (a procedure in which cells are scraped from the cervix and looked at under a microscope). Cervical cancer is almost always caused by human papillomavirus (HPV) infection.

Treatment with drugs that kill cancer cells.

A rare type of cancer that develops in cells that line the bile ducts in the liver. Cancer that forms where the right and left ducts meet is called Klatskin tumor.

A disease or condition that persists or progresses over a long period of time.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

Cancer that develops in the colon (the longest part of the large intestine) and/or the rectum (the last several inches of the large intestine before the anus).

A substance that is made by cells of the immune system. Some cytokines can boost the immune response and others can suppress it. Cytokines can also be made in the laboratory by recombinant DNA technology and used in the treatment of various diseases, including cancer.

Cell-killing.

A type of immune cell that can kill certain cells, including foreign cells, cancer cells, and cells infected with a virus. Cytotoxic T cells can be separated from other blood cells, grown in the laboratory, and then given to a patient to kill cancer cells. A cytotoxic T cell is a type of white blood cell and a type of lymphocyte. Also called cytotoxic T lymphocyte and killer T cell.

A special type of immune cell that is found in tissues, such as the skin, and boosts immune responses by showing antigens on its surface to other cells of the immune system. A dendritic cell is a type of phagocyte and a type of antigen-presenting cell (APC).

The molecules inside cells that carry genetic information and pass it from one generation to the next. Also called DNA.

The process of identifying a disease, such as cancer, from its signs and symptoms.

In cancer, refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and tend to grow and spread at a slower rate than undifferentiated or poorly differentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably.

The protein found on the surface of some cells and to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, so these cells may divide excessively in the presence of epidermal growth factor. Also called EGFR, ErbB1, and HER1.

Refers to the cells that line the internal and external surfaces of the body.

A common virus that remains dormant in most people. It causes infectious mononucleosis and has been associated with certain cancers, including Burkitt lymphoma, immunoblastic lymphoma, and nasopharyngeal carcinoma. Also called EBV.

In clinical trials, refers to a drug (including a new drug, dose, combination, or route of administration) or procedure that has undergone basic laboratory testing and received approval from the U.S. Food and Drug Administration (FDA) to be tested in human subjects. A drug or procedure may be approved by the FDA for use in one disease or condition, but be considered experimental in other diseases or conditions. Also called investigational.

A slender tube through which eggs pass from an ovary to the uterus. In the female reproductive tract, there is one ovary and one fallopian tube on each side of the uterus.

A condition marked by extreme tiredness and inability to function due lack of energy. Fatigue may be acute or chronic.

The developing offspring from 7 to 8 weeks after conception until birth.

An increase in body temperature above normal (98.6 degrees F), usually caused by disease.

An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

A plant-like organism that does not make chlorophyll. Mushrooms, yeasts, and molds are examples. The plural is fungi.

A complex molecule that contains both lipids (fats) and carbohydrates (sugars) and is found in the plasma (outer) membrane of many kinds of cells. Several different types of gangliosides have been identified.

Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

Refers to the genitalia (external and internal sex organs and glands).

A reproductive cell of the body. Germ cells are egg cells in females and sperm cells in males.

A fast-growing type of central nervous system tumor that forms from glial (supportive) tissue of the brain and spinal cord and has cells that look very different from normal cells. Glioblastoma usually occurs in adults and affects the brain more often than the spinal cord. Also called GBM, glioblastoma multiforme, and grade IV astrocytoma.

A short chain of amino acids (the building blocks of proteins) that has sugar molecules attached to it. Some glycopeptides have been studied for their ability to stimulate the immune system.

A protein that has sugar molecules attached to it.

A tumor-specific antigen used in the development of cancer vaccines. Also called glycoprotein 100.

A substance that helps make more white blood cells, especially granulocytes, macrophages, and cells that become platelets. It is a cytokine that is a type of hematopoietic (blood-forming) agent. Also called GM-CSF and sargramostim.

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.

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.

A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through blood or sexual contact. Also, infants born to infected mothers may become infected with the virus.

A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through blood or sexual contact. Also, infants born to infected mothers may become infected with the virus.

A type of adenocarcinoma, the most common type of liver tumor.

A protein involved in normal cell growth. It is found on some types of cancer cells, including breast and ovarian. Cancer cells removed from the body may be tested for the presence of HER2/neu to help decide the best type of treatment. HER2/neu is a type of receptor tyrosine kinase. Also called c-erbB-2, human EGF receptor 2, and human epidermal growth factor receptor 2.

A monoclonal antibody that binds to HER2 (human epidermal growth factor receptor 2), and can kill HER2-positive cancer cells. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Herceptin is used to treat breast cancer that is HER2-positive and has spread after treatment with other drugs. It is also used with other anticancer drugs to treat HER2-positive breast cancer after surgery. Herceptin is also being studied in the treatment of other types of cancer. Also called trastuzumab.

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 classical Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Symptoms include the painless enlargement of lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin disease.

A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV may cause cervical cancer. HPV may also play a role in some other types of cancer. Also called human papillomavirus.

A vaccine being studied in the prevention of human papillomavirus infection and cervical cancer. Infection with certain types of HPV increases the risk of developing cervical cancer. Also called human papillomavirus vaccine.

A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of human papillomavirus may cause cervical cancer. Human papillomavirus may also play a role in some other types of cancer. Also called HPV.

An exaggerated response by the immune system to a drug or other substance.

In medicine, a process that makes pictures of areas inside the body. Imaging uses methods such as x-rays (high-energy radiation), ultrasound (high-energy sound waves), and radio waves.

The activity of the immune system against foreign substances (antigens).

The complex group of organs and cells that defends the body against infections and other diseases.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.

Having to do with inflammation (redness, swelling, pain, and a feeling of heat that helps protect tissues affected by injury or disease).

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

A biological response modifier (a substance that can improve the body's natural response to infections and other diseases). Interferons interfere with the division of cancer cells and can slow tumor growth. There are several types of interferons, including interferon-alpha, -beta, and -gamma. The body normally produces these substances. They are also made in the laboratory to treat cancer and other diseases.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body. Interleukin-2 is made by a type of T lymphocyte. It increases the growth and activity of other T lymphocytes and B lymphocytes, and affects the development of the immune system. Aldesleukin (interleukin-2 made in the laboratory) is being used as a biological response modifier to boost the immune system in cancer therapy. Interleukin-2 is a type of cytokine. Also called IL-2.

A substance taken from a marine organism that may be linked to a specific antigen to boost the immune response to that antigen. Keyhole limpet hemocyanin is being studied as a way to increase the immune response to cancer vaccines. It is a type of immune modulator. Also called KLH.

A substance taken from a marine organism that may be linked to a specific antigen to boost the immune response to that antigen. KLH is being studied as a way to increase the immune response to cancer vaccines. It is a type of immune modulator. Also called keyhole limpet hemocyanin.

A type of immune cell. Most leukocytes are made in the bone marrow and are found in the blood and lymph tissue. Leukocytes help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are leukocytes. Also called WBC and white blood cell.

Fat.

Primary liver cancer is cancer that forms in the tissues of the liver. Secondary liver cancer is cancer that spreads to the liver from another part of the body.

A type of immune cell that is made in the bone marrow and is found in the blood and in lymph tissue. The two main types of lymphocytes are B lymphocytes and T lymphocytes. B lymphocytes make antibodies, and T lymphocytes help kill tumor cells and help control immune responses. A lymphocyte is a type of white blood cell.

Cancer that begins in cells of the immune system. There are two basic categories of lymphomas. One kind is Hodgkin lymphoma, which is marked by the presence of a type of cell called the Reed-Sternberg cell. The other category is non-Hodgkin lymphomas, which includes a large, diverse group of cancers of immune system cells. Non-Hodgkin lymphomas can be further divided into cancers that have an indolent (slow-growing) course and those that have an aggressive (fast-growing) course. These subtypes behave and respond to treatment differently. Both Hodgkin and non-Hodgkin lymphomas can occur in children and adults, and prognosis and treatment depend on the stage and the type of cancer.

A diagnostic indication that disease may develop.

Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.

A cell in the skin and eyes that produces and contains the pigment called melanin.

The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms. If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom). Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.

A type of protein made in the laboratory that can locate and bind to substances in the body, including tumor cells. There are many kinds of monoclonal antibodies. Each monoclonal antibody is made to find one substance. Monoclonal antibodies are being used to treat some types of cancer and are being studied in the treatment of other types. They can be used alone or to carry drugs, toxins, or radioactive materials directly to a tumor.

A mixture of oil and water that is combined with a specific antigen to boost the immune response to that antigen. It is being studied in immunotherapy and as a way to increase the immune response to cancer vaccines. It is a type of immune modulator. Also called IFA and incomplete Freund's adjuvant.

Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

The upper part of the throat behind the nose. An opening on each side of the nasopharynx leads into the ear.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

Cancer that arises in immature nerve cells and affects mostly infants and children.

Any of a large group of cancers of lymphocytes (white blood cells). Non-Hodgkin lymphomas can occur at any age and are often marked by lymph nodes that are larger than normal, fever, and weight loss. There are many different types of non-Hodgkin lymphoma. These types can be divided into aggressive (fast-growing) and indolent (slow-growing) types, and they can be formed from either B-cells or T-cells. B-cell non-Hodgkin lymphomas include Burkitt lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma, follicular lymphoma, immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, and mantle cell lymphoma. T-cell non-Hodgkin lymphomas include mycosis fungoides, anaplastic large cell lymphoma, and precursor T-lymphoblastic lymphoma. Lymphomas that occur after bone marrow or stem cell transplantation are usually B-cell non-Hodgkin lymphomas. Prognosis and treatment depend on the stage and type of disease. Also called NHL.

A group of lung cancers that are named for the kinds of cells found in the cancer and how the cells look under a microscope. The three main types of non-small cell lung cancer are squamous cell carcinoma, large cell carcinoma, and adenocarcinoma. Non-small cell lung cancer is the most common kind of lung cancer.

A part of the body that performs a specific function. For example, the heart is an organ.

A living thing, such as an animal, a plant, a bacterium, or a fungus.

Cancer that forms in tissues of the oropharynx (the part of the throat at the back of the mouth, including the soft palate, the base of the tongue, and the tonsils). Most oropharyngeal cancers are squamous cell carcinomas (cancer that begins in flat cells lining the oropharynx).

The part of the throat at the back of the mouth behind the oral cavity. It includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils.

A specific result or effect that can be measured. Examples of outcomes include decreased pain, reduced tumor size, and improvement of disease.

Cancer that forms in tissues of the ovary (one of a pair of female reproductive glands in which the ova, or eggs, are formed). Most ovarian cancers are either ovarian epithelial carcinomas (cancer that begins in the cells on the surface of the ovary) or malignant germ cell tumors (cancer that begins in egg cells).

In biology, to make too many copies of a protein or other substance. Overexpression of certain proteins or other substances may play a role in cancer development.

A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.

An animal or plant that gets nutrients by living on or in an organism of another species. A complete parasite gets all of its nutrients from the host organism, but a semi-parasite gets only some of its nutrients from the host.

Having to do with the pelvis (the lower part of the abdomen located between the hip bones).

A rare cancer that forms in the penis (an external male reproductive organ). Most penile cancers are squamous cell carcinomas (cancer that begins in flat cells lining the penis).

Cancer of the tissue that lines the abdominal wall and covers organs in the abdomen.

The hollow tube inside the neck that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach). The pharynx is about 5 inches long, depending on body size. Also called throat.

A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.

In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors (such as smoking, obesity, lack of exercise, and radiation exposure) and increasing protective factors (such as getting regular physical activity, staying at a healthy weight, and having a healthy diet).

Used to prevent disease.

In medicine, something that prevents or protects.

A protein made by the prostate gland and found in the blood. Prostate-specific antigen blood levels may be higher than normal in men who have prostate cancer, benign prostatic hyperplasia (BPH), or infection or inflammation of the prostate gland. Also called PSA.

A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

A protein made by the prostate gland and found in the blood. PSA blood levels may be higher than normal in men who have prostate cancer, benign prostatic hyperplasia (BPH), or infection or inflammation of the prostate gland. Also called prostate-specific antigen.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

One of two types of nucleic acid made by cells. Ribonucleic acid contains information that has been copied from DNA (the other type of nucleic acid). Cells make several different forms of ribonucleic acid, and each form has a specific job in the cell. Many forms of ribonucleic acid have functions related to making proteins. Ribonucleic acid is also the genetic material of some viruses instead of DNA. Ribonucleic acid can be made in the laboratory and used in research studies. Also called RNA.

A substance that helps make more white blood cells, especially granulocytes, macrophages, and cells that become platelets. It is a cytokine that is a type of hematopoietic (blood-forming) agent. Also called GM-CSF and granulocyte-macrophage colony-stimulating factor.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

An aggressive (fast-growing) cancer that forms in tissues of the lung and can spread to other parts of the body. The cancer cells look small and oval-shaped when looked at under a microscope.

A cancer that begins in the muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body.

The male reproductive cell, formed in the testicle. A sperm unites with an egg to form an embryo.

Cancer that forms in tissues lining the stomach. Also called gastric cancer.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Having to do with substances that are man-made instead of taken from nature.

A chronic, inflammatory, connective tissue disease that can affect the joints and many organs, including the skin, heart, lungs, kidneys, and nervous system. It can cause many different symptoms; however, not everyone with systemic lupus erythematosus has all of the symptoms. Also called lupus and SLE.

A type of immune cell that can attack foreign cells, cancer cells, and cells infected with a virus. T cells can also help control immune responses. A T cell is a type of white blood cell. Also called T lymphocyte and thymocyte.

A type of treatment that uses drugs or other substances, such as monoclonal antibodies, to identify and attack specific cancer cells. Targeted therapy may have fewer side effects than other types of cancer treatments.

One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testicle.

Having to do with treating disease and helping healing take place.

Treatment.

The hollow tube inside the neck that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach). The throat is about 5 inches long, depending on body size. Also called pharynx.

A group or layer of cells that work together to perform a specific function.

One of two small masses of lymphoid tissue on either side of the throat.

Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.

A monoclonal antibody that binds to HER2 (human epidermal growth factor receptor 2), and can kill HER2-positive cancer cells. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Trastuzumab is used to treat breast cancer that is HER2-positive and has spread after treatment with other drugs. It is also used with other anticancer drugs to treat HER2-positive breast cancer after surgery. Trastuzumab is also being studied in the treatment of other types of cancer. Also called Herceptin.

A disease caused by a specific type of bacteria that spreads from one person to another through the air. Tuberculosis can affect many parts of the body, but most often affects the lungs. A person may not have symptoms of tuberculosis for years, but they may appear when the patient becomes ill with a serious condition like diabetes, AIDS, or cancer. Tuberculosis can usually be treated and cured with antibiotics. Also called TB.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

A type of gene that makes a protein called a tumor suppressor protein that helps control cell growth. Mutations (changes in DNA) in tumor suppressor genes may lead to cancer. Also called antioncogene.

A protein that is made from tumor cells and is used in a vaccine against melanoma. A tyrosinase peptide vaccine may stimulate the body's immune system to find and kill melanoma cells.

Treated with a vaccine.

Treatment with a vaccine.

A substance or group of substances meant to cause the immune system to respond to a tumor or to microorganisms, such as bacteria or viruses. A vaccine can help the body recognize and destroy cancer cells or microorganisms.

Cancer that forms in the tissues of the vagina (birth canal). The vagina leads from the cervix (the opening of the uterus) to the outside of the body. The most common type of vaginal cancer is squamous cell carcinoma, which starts in the thin, flat cells lining the vagina. Another type of vaginal cancer is adenocarcinoma, cancer that begins in glandular cells in the lining of the vagina.

In medicine, a very simple microorganism that infects cells and may cause disease. Because viruses can multiply only inside infected cells, they are not considered to be alive.

To eject some or all of the contents of the stomach through the mouth.

Cancer of the vulva (the external female genital organs, including the clitoris, vaginal lips, and the opening to the vagina).

A raised growth on the surface of the skin or other organ.

A type of immune cell. Most white blood cells are made in the bone marrow and are found in the blood and lymph tissue. White blood cells help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are white blood cells. Also called leukocyte and WBC.