Cancer Glossary - T

T cell   One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells. T cells also produce a number of substances that regulate the immune response.

T-3   A thyroid hormone. Also called triiodothyronine or liothyronine sodium.

T-cell depletion   Treatment to destroy T cells, which play an important role in the immune response. Elimination of T cells from a bone marrow graft from a donor may reduce the chance of an immune reaction against the recipient's tissues.

T-cell lymphoma  (lim-FO-ma) A disease in which certain cells of the lymph system (called T lymphocytes) become cancerous.

T138067   An anticancer drug that belongs to the family of drugs called mitotic inhibitors. It inhibits the growth of cancer cells by preventing cell division.

T4N5 liposomal lotion   Enzyme lotion used in treating xeroderma pigmentosum.

tacrolimus   A drug used to help reduce the risk of rejection by the body of organ and bone marrow transplants.

TAG-72 antigen   A protein/sugar complex found on the surface of many cancer cells, including breast, colon, and pancreatic cells.

tamoxifen   An anticancer drug that belongs to the family of drugs called antiestrogens. Tamoxifen blocks the effects of the hormone estrogen in the body. It is used to prevent or delay the return of breast cancer or to control its spread.

taurolidine   A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called anti-infectives.

taxanes   Anticancer drugs that inhibit cancer cell growth by stopping cell division. Also called antimitotic or antimicrotubule agents or mitotic inhibitors.

technetium Tc 99m dextran   A radiolabeled substance that is used in cancer diagnosis.

technetium Tc 99m sulfur colloid   A radiolabeled substance that is used to help identify sites of tumor development.

tegafur   An anticancer drug that belongs to the family of drugs called antimetabolites.

telangiectasia  (tel-AN-gee-ek-TAY-zha) The permanent enlargement of blood vessels, causing redness in the skin or mucous membranes.

temoporfin   An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents.

temozolomide   An anticancer drug that belongs to the family of drugs called alkylating agents.

teniposide   An anticancer drug that is a podophyllotoxin derivative and belongs to the family of drugs called mitotic inhibitors.

TENS   Transcutaneous electric nerve stimulation. A technique in which mild electric currents are applied to some areas of the skin by a small power pack connected to two electrodes.

teratoma   (ter-a-TOW-ma) A type of germ cell tumor that may contain several different types of tissue, such as hair, muscle, and bone. Teratomas occur most often in the ovaries in women, the testicles in men, and the tailbone in children. Not all teratomas are malignant.

terminal disease   Disease that cannot be cured and will cause death.

testicles  (TES-tih-kuls) The two egg-shaped glands found inside the scrotum. They produce sperm and male hormones. Also called testes.

testimonials   Information provided by individuals who claim to have been helped or cured by a particular product. The information provided lacks the necessary elements to be evaluated in a rigorous and scientific manner and is not used in the scientific literature.

testosterone  (tes-TOS-ter-own) A hormone that promotes the development and maintenance of male sex characteristics.

tetracycline   An antibiotic drug used to treat infection.

TG4010   A substance that is being studied as an anticancer drug.

thalamus  (THAL-a-muss) An area of the brain that helps process information from the senses and transmit it to other parts of the brain.

thalidomide   A drug that belongs to the family of drugs called angiogenesis inhibitors. It prevents the growth of new blood vessels into a solid tumor.

theophylline   A drug used to improve breathing in people who are short of breath. It belongs to the family of drugs called bronchodilators or respiratory smooth muscle relaxants.

therapeutic   Used to treat disease and help healing take place.

therapy   Treatment.

thermal ablation   A procedure using heat to remove tissue or a part of the body, or destroy its function. For example, to remove the lining of the uterus, a catheter is inserted through the cervix into the uterus, a balloon at the end of the catheter is inflated, and fluid inside the balloon is heated to destroy the lining of the uterus.

thioguanine   An anticancer drug that belongs to the family of drugs called antimetabolites.

thiotepa   An anticancer drug that belongs to the family of drugs called alkylating agents.

thoracentesis  (thor-a-sen-TEE-sis) Removal of fluid from the pleural cavity through a needle inserted between the ribs.

thoracic  (thor-ASS-ik) Having to do with the chest.

thoracoscopy   The use of a thin, lighted tube (called an endoscope) to examine the inside of the chest.

thoracotomy  (thor-a-KAH-toe-mee) An operation to open the chest.

thrombocytes  (THROM-bo-sites) Blood cells that help prevent bleeding by causing blood clots to form. Also called platelets.

thrombocytopenia   A decrease in the number of platelets in the blood that may result in easy bruising and excessive bleeding from wounds or bleeding in mucous membranes and other tissues.

thrombophlebitis  (throm-bo-fleh-BY-tis) Inflammation of a vein that occurs when a blood clot forms.

thrombopoietin   A colony-stimulating factor that stimulates the production of blood cells, especially platelets, during chemotherapy. It is a cytokine that belongs to the family of drugs called hematopoietic (blood forming) agents.

thrombosis  (throm-BOW-sis) The formation or presence of a blood clot inside a blood vessel.

thrush   A condition in which Candida albicans, a type of yeast, grows out of control in moist skin areas of the body. It is usually a result of a weakened immune system, but can be a side effect of chemotherapy or treatment with antibiotics. Thrush usually affects the mouth (oral thrush); however, rarely, it spreads throughout the entire body. Also called Candidiasis or Candidosis.

thymidine   A chemical compound found in DNA. Also used as treatment for mucositis.

thymoma   A tumor of the thymus, an organ that is part of the lymphatic system and is located in the chest, behind the breastbone.

thymus   An organ that is part of the lymphatic system, in which T lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.

thyroglobulin  (THIGH-roe-GLOB-yu-lin) The form that thyroid hormone takes when stored in the cells of the thyroid. If the thyroid has been removed, thyroglobulin should not show up on a blood test. Doctors measure thyroglobulin level in blood to detect thyroid cancer cells that remain in the body after treatment.

thyroid   A gland located beneath the voice box (larynx) that produces thyroid hormone. The thyroid helps regulate growth and metabolism.

thyroid follicular cell   A type of cell in the thyroid. Thyroid follicular cells make thyroid hormone.

thyroid gland  (THIGH-royd) A gland located beneath the voice box (larynx) that produces thyroid hormone. The thyroid helps regulate growth and metabolism.

thyroid hormone   The thyroid gland makes T3 (triiodothyronine) and T4 (thyroxine), which together are considered thyroid hormone. T3 and T4 have identical effects on cells. Thyroid hormone affects heart rate, blood pressure, body temperature, and weight. T3 and T4 are stored as thyroglobulin, which can be converted back into T3 and T4.

thyroid-stimulating hormone   TSH. A hormone produced by the pituitary gland. TSH stimulates the release of thyroid hormone from thyroglobulin. It also stimulates the growth of thyroid follicular cells. An abnormal TSH level may mean that the thyroid hormonal regulation system is out of control, usually as a result of a benign condition (hyperthyroidism or hypothyroidism).

thyroidectomy  (thigh-roid-EK-toe-mee) Surgery to remove part or all of the thyroid.

tiazofurin   An anticancer drug being studied to stop cell growth.

time to progression   A measure of time after a disease is diagnosed (or treated) until the disease starts to get worse.

tin ethyl etiopurpurin   An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents. Also called SnET2.

tin Sn 117m DTPA   A radioactive chemical being studied to treat bone pain associated with cancer.

tinidazole   A drug used to treat protozoal infections, such as amebiasis, giardiasis, and trichomoniasis. It belongs to a family of drugs called antiprotozoal agents. Tinidazole is also being evaluated in the treatment of Helicobacter pylori infections in people with low-grade gastric lymphoma.

tirapazamine   A drug that makes tumor cells more sensitive to radiation therapy.

tissue  (TISH-oo) A group or layer of cells that are alike and that work together to perform a specific function.

tissue flap reconstruction   A type of breast reconstruction in which a flap of tissue is surgically moved from another area of the body to the chest, and formed into a new breast mound.

TLK286   A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called glutathione analogs.

TM   Transcendental meditation. A mental technique used to promote relaxation, reduce stress, and improve quality of life.

TNF   Tumor necrosis factor. A type of biological response modifier (a substance that can improve the body's natural response to disease).

TNP-470   A drug that belongs to the family of drugs called angiogenesis inhibitors. It prevents the growth of new blood vessels into a solid tumor.

tocladesine   A substance that is being studied as an anticancer drug. It is an analogue of a substance that occurs naturally in the body (cyclic adenosine monophosphate).

tomography  (tuh-MAH-gra-fee) A series of detailed pictures of areas inside the body; the pictures are created by a computer linked to an x-ray machine.

tonsils   Small masses of lymphoid tissue on either side of the throat.

topical   On the surface of the body.

topical chemotherapy  (kee-mo-THER-a-pee) Treatment with anticancer drugs in a lotion or cream applied to the skin.

topoisomerase inhibitors   A family of anticancer drugs. The topoisomerase enzymes are responsible for the arrangement and rearrangement of DNA in the cell and for cell growth and replication. Inhibiting these enzymes may kill cancer cells or stop their growth.

topotecan   An anticancer drug that belongs to the family drugs called topoisomerase inhibitors.

toremifene   An anticancer drug that belongs to the family of drugs called antiestrogens. Toremifene blocks the effect of the hormone estrogen in the body. It may help control some cancers from growing, and it may delay or reduce the risk of cancer recurrence.

total androgen blockade   Therapy used to eliminate male sex hormones (androgens) in the body. This may be done with surgery, hormonal therapy, or a combination.

total estrogen blockade   Therapy used to eliminate estrogen in the body. This may be done with surgery, radiation therapy, chemotherapy, or a combination of these procedures.

total hysterectomy   Surgery to remove the entire uterus, including the cervix. Sometimes, not all of the cervix is removed. Also called complete hysterectomy.

total mastectomy  (mas-TEK-toe-mee) Removal of the breast. Also called simple mastectomy.

total nodal irradiation   Radiation therapy to the mantle field, the spleen, the lymph nodes in the upper abdomen, and the lymph nodes in the pelvic area.

total pancreatectomy   Surgery to remove the entire pancreas.

total parenteral nutrition   TPN. Intravenous (into a vein) feeding that provides necessary nutrients when a person is unable to eat normally.

total-body irradiation   Radiation therapy to the entire body. Usually followed by bone marrow or peripheral stem cell transplantation.

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

toxins   Poisons produced by certain animals, plants, or bacteria.

TPA   12-O-tetradecanoylphorbol-13-acetate. A drug that is being studied as a treatment for hematologic cancer.

trace element   A chemical found in very small amounts in a substance or mixture.

tracer   A substance (such as a radioisotope) used in imaging procedures.

trach tube   A 2-inch- to 3-inch-long curved metal or plastic tube placed in a surgically created opening (tracheostomy) in the windpipe to keep it open. Also called a tracheostomy tube.

trachea  (TRAY-kee-a) The airway that leads from the larynx to the lungs. Also called the windpipe.

tracheoesophageal puncture  (TRAY-kee-o-eh-SOF-a-JEE-al PUNK-chur) A small opening made by a surgeon between the esophagus and the trachea. A valve keeps food out of the trachea but lets air into the esophagus for esophageal speech.

tracheostomy  (TRAY-kee-AHS-toe-mee) Surgery to create an opening (stoma) into the windpipe. The opening itself may also be called a tracheostomy.

tracheostomy button  (TRAY-kee-AHS-toe-mee) A 0.5-inch- to 1.5-inch-long plastic tube placed in a surgically created opening (tracheostomy) in the windpipe to keep it open.

tracheostomy tube  (TRAY-kee-AHS-toe-mee) A 2-inch- to 3-inch-long curved metal or plastic tube placed in a surgically created opening (tracheostomy) in the windpipe to keep it open. Also called a trach ("trake") tube.

transabdominal ultrasound   A procedure used to examine the organs in the abdomen. The ultrasound device is pressed firmly against the skin of the abdomen. Sound waves from the device bounce off tissues and create echoes. A computer uses the echoes to make a picture called a sonogram.

transcendental meditation   TM. A mental technique used to promote relaxation, reduce stress, and improve quality of life.

transcutaneous electric nerve stimulation   TENS. A technique in which mild electric currents are applied to some areas of the skin by a small power pack connected to two electrodes.

transdermal   Through the skin.

transformation   The change that a normal cell undergoes as it becomes malignant.

transfusion  (trans-FYOO-zhun) The infusion of components of blood or whole blood into the bloodstream. The blood may be donated from another person, or it may have been taken from the person earlier and stored until needed.

transitional cell carcinoma   A type of cancer that develops in the lining of the bladder, ureter, or renal pelvis.

transitional cells   Cells that vary in shape depending on whether the tissue is being stretched. The cells may be stretched without breaking apart. They line hollow organs such as the bladder.

transplant surgeon   A doctor who specializes in transplantation surgery. The surgeon replaces a patient's organ with an organ from another person.

transplantation   The replacement of an organ with one from another person.

transrectal ultrasound   A procedure used to examine the prostate. An instrument is inserted into the rectum, and sound waves bounce off the prostate. These sound waves create echoes, which a computer uses to create a picture called a sonogram.

transurethral resection  (TRANZ-yoo-REE-thral ree-SEK-shun) Surgery performed with a special instrument inserted through the urethra. Also called TUR.

transurethral resection of the prostate  (TRANZ-yoo-REE-thral ree-SEK-shun) Surgical procedure to remove tissue from the prostate using an instrument inserted through the urethra. Also called TURP.

transvaginal ultrasound   A procedure used to examine the vagina, uterus, fallopian tubes, and bladder. An instrument is inserted into the vagina, and sound waves bounce off organs inside the pelvic area. These sound waves create echoes, which a computer uses to create a picture called a sonogram. Also called TVS.

trastuzumab   A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells. Trastuzumab blocks the effects of the growth factor protein HER2, which transmits growth signals to breast cancer cells.

treatment field   In radiation therapy, the place on the body where the radiation beam is aimed.

treosulfan   A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called alkylating agents.

tretinoin   A drug that belongs to the family of drugs called retinoids. It is used in the treatment of acne and is being studied in cancer prevention.

triacetyluridine   A substance that is being studied for its ability to protect against the gastrointestinal side effects caused by fluorouracil. It is a precursor of uridine, which is a component of RNA.

triamcinolone  (try-am-SIN-oh-lone) A substance that is being studied for the prevention of nonmelanoma skin cancer. It is an anti-inflammatory drug that is applied to the skin to relieve irritation, rashes, and infections. It belongs to the family of drugs called topical corticosteroids.

tributyrin   A triglyceride drug that may inhibit cell growth and induce cell differentiation. Differentiating agents may be effective in changing cancer cells back into normal cells.

trichothiodystrophy   A hereditary condition characterized by sparse and brittle hair, short stature, and mental retardation.

triiodothyronine   A thyroid hormone. Also called liothyronine sodium or T-3.

trimethoprim-sulfamethoxazole   An antibiotic drug used to treat infection and prevent pneumocystis carinii pneumonia.

trimetrexate glucuronate   A drug that belongs to the family of drugs called antimetabolites. It is used in the treatment of pneumocystis carinii pneumonia and is being studied in the treatment of cancer.

triptorelin   A hormonal anticancer drug that belongs to the family of drugs called gonadotropin-releasing analogues.

troglitazone   A drug used in diabetes treatment that is being studied for its effect on reducing the risk of cancer cell growth in fat tissue.

troxacitabine   A drug being studied for use as an anticancer agent.

tubal ligation  (TOO-bul lye-GAY-shun) An operation to tie the fallopian tubes closed. This procedure prevents pregnancy by blocking the passage of eggs from the ovaries to the uterus.

tumor  (TOO-mer) An abnormal mass of tissue that results from excessive cell division. Tumors perform no useful body function. They may be benign (not cancerous) or malignant (cancerous).

tumor antigen vaccine   A vaccine made of tumor antigens (proteins isolated from tumor cells).

tumor burden   Refers to the number of cancer cells or the amount of cancer in the body.

tumor debulking   Surgically removing as much of the tumor as possible.

tumor infiltrating lymphocytes   White blood cells that have left the bloodstream and migrated into a tumor.

tumor marker   A substance sometimes found in an increased amount in the blood, other body fluids, or tissues and which may mean that a certain type of cancer is in the body. Examples of tumor markers include CA 125 (ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (prostate cancer). Also called biomarker.

tumor model   A type of animal model which can be used to study the development and progression of diseases and to test new treatments before they are given to humans. Animals with transplanted human cancers or other tissues are called xenograft models.

tumor necrosis factor  (TOO-mer ne-KRO-sis) A type of biological response modifier (a substance that can improve the body's natural response to disease). Three types of tumor necrosis factor have been identified: alpha, beta, and gamma. Tumor necrosis factor seems to play a role in the breakdown of cancer cells.

tumor suppressor gene  (TOO-mer) Genes in the body that can suppress or block the development of cancer.

tumor-derived   Taken from an individual's own tumor tissue; may be used in the development of a vaccine that enhances the body's ability to build an immune response to the tumor.

tumor-specific antigen   A protein or other molecule that is unique to cancer cells or is much more abundant in them. These molecules are usually found in the plasma (outer) membrane, and they are thought to be potential targets for immunotherapy or other types of anticancer treatment.

TUR   Surgery performed with a special instrument inserted through the urethra. Also called transurethral resection.

TURP   Surgical procedure to remove tissue from the prostate using an instrument inserted through the urethra. Also called transurethral resection of the prostate.

TVS   A procedure used to examine the vagina, uterus, fallopian tubes, and bladder. An instrument is inserted into the vagina, and sound waves bounce off organs inside the pelvic area. These sound waves create echoes, which a computer uses to create a picture called a sonogram. Also called transvaginal ultrasound.

tyrosinase peptide   A tumor-specific antigen used in the development of cancer vaccines.