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Medical Glossary

T

  • T cell
  • 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.
  • T lymphocyte
  • A type of immune cell that can attack foreign cells, cancer cells, and cells infected with a virus. T lymphocytes can also help control immune responses. A T lymphocyte is a type of white blood cell. Also called T cell and thymocyte.
  • T reg
  • A type of immune cell that blocks the actions of some other types of lymphocytes, to keep the immune system from becoming over-active. T regs are being studied in the treatment of cancer. A T reg is a type of white blood cell and a type of lymphocyte. Also called regulatory T cell, suppressor T cell, and T-regulatory cell.
  • t test
  • A statistical test that is used to find out if there is a real difference between the means (averages) of two different groups. It is sometimes used to see if there is a significant difference in response to treatment between groups in a clinical trial.
  • 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.
  • T-3
  • A thyroid hormone. Also called triiodothyronine.
  • T4N5 liposomal lotion
  • A hormone that is made by the thyroid gland and contains iodine. T4 increases the rate of chemical reactions in cells and helps control growth and development. T4 can also be made in the laboratory and is used to treat thyroid disorders. Also called L-3,5,5’-tetraiodothyronine, thyroxin, and thyroxine.
  • T900607
  • A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called tubulin-binding agents.
  • TAC-101
  • A substance that is being studied in the treatment of cancer. It belongs to the families of drugs called synthetic retinoids and angiogenesis inhibitors.
  • tachycardia
  • Rapid beating of the heart, usually defined as greater than 100 beats per minute.
  • tachypnea
  • Rapid breathing.
  • 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.
  • tai chi
  • A form of traditional Chinese mind/body exercise and meditation that uses slow sets of body movements and controlled breathing. Tai chi is done to improve balance, flexibility, muscle strength, and overall health.
  • tailbone
  • The small bone at the bottom of the spine. It is made up of 3-5 fused bones. Also called coccyx.
  • tailored intervention
  • The use of communication, drugs, or other types of treatments that are specific for an individual or a group to improve health or change behavior.
  • talabostat
  • A substance being studied in the treatment of cancer, including certain types of lung, pancreas, and brain cancer. Talabostat may help the immune system block the growth of cancer cells. It may also increase the growth of new blood cells. It is a type of enzyme inhibitor. Also called PT-100 and talabostat mesylate.
  • talabostat mesylate
  • A substance being studied in the treatment of cancer, including certain types of lung, pancreas, and brain cancer. Talabostat mesylate may help the immune system block the growth of cancer cells. It may also increase the growth of new blood cells. It is a type of enzyme inhibitor. Also called PT-100 and talabostat.
  • talactoferrin
  • A drug being studied in the treatment of kidney cancer that has spread. It is also being studied in the treatment of other types of cancer and other conditions. Talactoferrin increases the activity of dendritic cells (a type of immune cell) to help kill cancer cells. It is a form of human lactoferrin (a protein found in milk, tears, mucus, bile, and some white blood cells) that is made in the laboratory. Talactoferrin is a type of recombinant protein and a type of immunomodulatory protein. Also called talactoferrin alfa and TLF.
  • talactoferrin alfa
  • A drug being studied in the treatment of kidney cancer that has spread. It is also being studied in the treatment of other types of cancer and other conditions. Talactoferrin alfa increases the activity of dendritic cells (a type of immune cell) to help kill cancer cells. It is a form of human lactoferrin (a protein found in milk, tears, mucus, bile, and some white blood cells) that is made in the laboratory. Talactoferrin alfa is a type of recombinant protein and a type of immunomodulatory protein. Also called talactoferrin and TLF.
  • talampanel
  • A substance that is being studied in the treatment of brain tumors and other brain disorders, such as epilepsy and Parkinson disease. It is a type of AMPA receptor antagonist.
  • talaporfin sodium
  • A drug used in photodynamic therapy. When absorbed by cancer cells and exposed to light, the drug becomes active and kills the cancer cells.
  • talc
  • A mineral, usually used in a powdered form. In cancer treatment, sterile talc is used to prevent pleural effusions (an abnormal collection of fluid in the space between the lungs and the chest wall). Talc is inserted into the space, causing it to close up, so fluid cannot collect there. Also called sterile talc powder.
  • talk therapy
  • Treatment of mental, emotional, personality, and behavioral disorders using methods such as discussion, listening, and counseling. Also called psychotherapy.
  • talotrexin
  • A substance that is being studied in the treatment of leukemia and some other types of cancer. It belongs to the family of drugs called antifolates.
  • Tamiflu
  • A drug used to prevent and to treat influenza virus infections. It blocks the release of the virus from infected cells. It is a type of antiviral agent. Also called oseltamivir phosphate.
  • tamoxifen
  • A drug used to treat certain types of breast cancer in women and men. It is also used to prevent breast cancer in women who have had ductal carcinoma in situ (abnormal cells in the ducts of the breast) and in women who are at a high risk of developing breast cancer. Tamoxifen is also being studied in the treatment of other types of cancer. It blocks the effects of the hormone estrogen in the breast. Tamoxifen is a type of antiestrogen. Also called tamoxifen citrate.
  • tamoxifen citrate
  • A drug used to treat certain types of breast cancer in women and men. It is also used to prevent breast cancer in women who have had ductal carcinoma in situ (abnormal cells in the ducts of the breast) and in women who are at a high risk of developing breast cancer. Tamoxifen citrate is also being studied in the treatment of other types of cancer. It blocks the effects of the hormone estrogen in the breast. Tamoxifen citrate is a type of antiestrogen. Also called tamoxifen.
  • tamsulosin
  • A drug used to treat urinary problems caused by an enlarged prostate. Tamsulosin relaxes the muscles of the prostate and bladder, which helps the flow of urine. It is a type of alpha blocker. Also called Flomax and tamsulosin hydrochloride.
  • tamsulosin hydrochloride
  • A drug used to treat urinary problems caused by an enlarged prostate. Tamsulosin hydrochloride relaxes the muscles of the prostate and bladder, which helps the flow of urine. It is a type of alpha blocker. Also called Flomax and tamsulosin.
  • tandutinib
  • A substance being studied in the treatment of some types of cancer. It may stop cancer cell growth by blocking certain enzymes. It may also prevent the growth of new blood vessels that tumors need to grow. It is a type of tyrosine kinase inhibitor and a type of antiangiogenesis agent. Also called CT53518 and MLN518.
  • tanespimycin
  • A substance being studied in the treatment of cancer. It is made from an antibiotic called geldanamycin. Tanespimycin helps cause the breakdown of certain proteins in the cell, and may kill cancer cells. It is a type of antineoplastic antibiotic and a type of HSP90 inhibitor. Also called 17-AAG and 17-N-allylamino-17-demethoxygeldanamycin.
  • Tarceva
  • A drug used to treat certain types of non-small cell lung cancer. It is also used together with gemcitabine to treat pancreatic cancer and is being studied in the treatment of other types of cancer. Tarceva is a type of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. Also called CP-358,774, erlotinib, erlotinib hydrochloride, and OSI-774.
  • targeted therapy
  • 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.
  • Targretin
  • A drug used to treat skin problems caused by cutaneous T-cell lymphoma that have not gotten better after other treatment. It is also being studied in the treatment of other types of cancer. Targretin is a type of retinoid. Also called bexarotene and LGD1069.
  • tariquidar
  • A substance that is being studied in the treatment of cancer. It may help tumor cells respond again to drugs they have become resistant (unable to respond) to. Tariquidar is a type of multidrug resistance inhibitor and a type of P-glycoprotein antagonist. Also called XR9576.
  • Tasigna
  • A drug used to treat certain types of chronic myelogenous leukemia (CML). It is used in patients who have not gotten better after treatment with other anticancer drugs or who are not able to take imatinib mesylate. It is also being studied in the treatment of other types of cancer. Tasigna blocks a protein called BCR/ABL which is made in CML cells that contain the Philadelphia chromosome (an abnormal chromosome 22 that has part of chromosome 9 attached). It is a type of tyrosine kinase inhibitor. Also called nilotinib.
  • taurolidine
  • A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called anti-infectives.
  • taxane
  • A type of drug that blocks cell growth by stopping mitosis (cell division). Taxanes interfere with microtubules (cellular structures that help move chromosomes during mitosis). They are used to treat cancer. A taxane is a type of mitotic inhibitor and antimicrotubule agent.
  • Taxol
  • A drug used to treat breast cancer, ovarian cancer, and AIDS-related Kaposi sarcoma. It is also used together with another drug to treat non-small cell lung cancer. Taxol is also being studied in the treatment of other types of cancer. It blocks cell growth by stopping cell division and may kill cancer cells. It is a type of antimitotic agent. Also called paclitaxel.
  • Taxotere
  • A drug used together with other drugs to treat certain types of breast cancer, stomach cancer, prostate cancer, and certain types of head and neck cancer. It is also being studied in the treatment of other types of cancer. Taxotere is a type of mitotic inhibitor. Also called docetaxel.
  • tazarotene
  • A drug used on the skin to treat several skin conditions. It is also being studied in the treatment of basal cell skin cancer and basal cell nevus syndrome. Tazarotene is related to vitamin A and is made in the laboratory. It turns on a gene that may help stop the growth of skin cancer cells. Tazarotene is a type of synthetic retinoid. Also called Avage and Tazorac.
  • Tazorac
  • A drug used on the skin to treat several skin conditions. It is also being studied in the treatment of basal cell skin cancer and basal cell nevus syndrome. Tazorac is related to vitamin A and is made in the laboratory. It turns on a gene that may help stop the growth of skin cancer cells. Tazorac is a type of synthetic retinoid. Also called Avage and tazarotene.
  • TB
  • A disease caused by a specific type of bacteria that spreads from one person to another through the air. TB can affect many parts of the body, but most often affects the lungs. A person may not have symptoms of TB for years, but they may appear when the patient becomes ill with a serious condition like diabetes, AIDS, or cancer. TB can usually be treated and cured with antibiotics. Also called tuberculosis.
  • TCE
  • A device used to look at tissues in the esophagus. It is a tiny capsule with a laser scanner inside and a very thin cord attached to it. The patient swallows the capsule and the thin cord helps keep the capsule in a specific area in the esophagus. The cord is also used to remove the capsule. Pictures are taken by the laser scanner and sent to a computer for viewing. A TCE is used to find early cancers of the esophagus and other parts of the body. Also called tethered capsule endoscope.
  • T-cell acute lymphoblastic leukemia
  • An aggressive (fast-growing) type of leukemia (blood cancer) in which too many T-cell lymphoblasts (immature white blood cells) are found in the bone marrow and blood. Also called precursor T-lymphoblastic leukemia and T-cell acute lymphocytic leukemia.
  • T-cell acute lymphocytic leukemia
  • An aggressive (fast-growing) type of leukemia (blood cancer) in which too many T-cell lymphoblasts (immature white blood cells) are found in the bone marrow and blood. Also called precursor T-lymphoblastic leukemia and T-cell acute lymphoblastic leukemia.
  • 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 large granular lymphocyte leukemia
  • A type of leukemia in which large T lymphocytes (a type of white blood cell) that contain granules (small particles) are found in the blood. It is a chronic disease that may last for a long time and get worse. Also called T-LGL leukemia.
  • T-cell lymphoma
  • A disease in which certain cells of the lymph system (called T lymphocytes) become cancer.
  • TCM
  • A medical system that has been used for thousands of years to prevent, diagnose, and treat disease. It is based on the belief that qi (the body's vital energy) flows along 20 meridians (channels) throughout the body and keeps a person’s spiritual, emotional, mental, and physical health in balance. TCM aims to restore the body’s balance and harmony between the natural opposing forces of yin and yang, which can block qi and cause disease. TCM includes acupuncture, diet, herbal therapy, meditation, physical exercise, and massage. Also called Oriental medicine and traditional Chinese medicine.
  • tea tree
  • A tree that is a member of the myrtle family. Oil from the tea tree is used in shampoos and skin care products and to treat skin infections. It has been used in some cultures to treat other skin conditions, including acne, burns, and insect bites. The scientific name is Melaleuca alternifolia .
  • technetium Tc 94m sestamibi
  • A substance being studied in certain cancer-imaging tests using positron emission tomography (PET). It contains a radioactive substance called technetium, bound to another substance called sestamibi, that helps it enter cells. It may help show how well cancer cells take up anticancer drugs. It is a type of radiopharmaceutical.
  • 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.
  • technician
  • A person trained in the techniques (methods) and skills of a profession. For example, a mammogram technician is trained to perform mammograms.
  • tegafur
  • An anticancer drug that belongs to the family of drugs called antimetabolites.
  • tegafur-uracil
  • 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. Tegafur-uracil is a type of antimetabolite. Also called Ftorafur, UFT, and Uftoral.
  • teicoplanin
  • A substance used to treat bacterial infections. It belongs to the family of drugs called antibiotics.
  • telangiectasia
  • The permanent enlargement of blood vessels, causing redness in the skin or mucous membranes.
  • Telcyta
  • A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called glutathione analogs. Also called TLK286.
  • telemedicine
  • The delivery of healthcare from a distance using electronic information and technology such as computers, cameras, videoconferencing, the Internet, satellite, and wireless communications.
  • telomerase
  • An enzyme in cells that helps keep them alive by adding DNA to telomeres (the ends of chromosomes). Each time a cell divides, the telomeres lose a small amount of DNA and become shorter. Over time, the chromosomes become damaged and the cells die. Telomerase helps keep this from happening. Cancer cells usually have more telomerase than most normal cells.
  • telomere
  • The ends of a chromosome. Each time a cell divides, the telomeres lose a small amount of DNA and become shorter. Over time, the chromosomes become damaged and the cells die. In cancer cells the telomeres do not get shorter, and may become longer, as the cells divide.
  • Temodar
  • A drug that is used to treat certain types of brain tumors in adults and is being studied in the treatment of other types of cancer. It belongs to the family of drugs called alkylating agents. Also called temozolomide.
  • temoporfin
  • An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents.
  • temozolomide
  • A drug that is used to treat certain types of brain tumors in adults and is being studied in the treatment of other types of cancer. It belongs to the family of drugs called alkylating agents. Also called Temodar.
  • temsirolimus
  • A drug used to treat advanced renal cell carcinoma (a type of kidney cancer). It is also being studied in the treatment of other types of cancer. Temsirolimus blocks a protein involved in cell division, and may kill cancer cells. It is a type of rapamycin analog and a type of serine/threonine kinase inhibitor. Also called CCI-779 and Torisel.
  • tendon
  • Tough, fibrous, cord-like tissue that connects muscle to bone or another structure, such as an eyeball. Tendons help the bone or structure to move.
  • teniposide
  • An anticancer drug that is a podophyllotoxin derivative and belongs to the family of drugs called mitotic inhibitors.
  • TENS
  • A procedure in which mild electric currents are applied to some areas of the skin. Also called transcutaneous electrical nerve stimulation.
  • teratocarcinoma
  • A type of germ cell cancer that usually forms in the testes (testicles).
  • teratoma
  • 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.
  • terazosin
  • A drug used to treat urinary problems caused by an enlarged prostate. It is also used to treat high blood pressure and is being studied in the treatment of other conditions. Terazosin relaxes muscle tissue in blood vessels and in the prostate. It is a type of alpha blocker. Also called Hytrin and terazosin hydrochloride.
  • terazosin hydrochloride
  • A drug used to treat urinary problems caused by an enlarged prostate. It is also used to treat high blood pressure and is being studied in the treatment of other conditions. Terazosin hydrochloride relaxes muscle tissue in blood vessels and in the prostate. It is a type of alpha blocker. Also called Hytrin and terazosin.
  • terminal disease
  • Disease that cannot be cured and will cause death.
  • terpene
  • A type of strong-smelling chemical substance found in some plants, especially trees that have cones. Terpenes are found in essential oils (scented liquid taken from plants).
  • testicle
  • One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testis.
  • testicular cancer
  • Cancer that forms in tissues of the testis (one of two egg-shaped glands inside the scrotum that make sperm and male hormones). Testicular cancer usually occurs in young or middle-aged men. Two main types of testicular cancer are seminomas (cancers that grow slowly and are sensitive to radiation therapy) and nonseminomas (different cell types that grow more quickly than seminomas).
  • testicular cord
  • A cord-like structure in the male reproductive system that contains nerves, blood and lymph vessels, and the vas deferens (a coiled tube that carries sperm out of the testicle). It runs from the abdomen to the testicle, and connects to the testicle in the scrotum (external sac). Also called spermatic cord.
  • testimonial
  • Information provided by an individual who claims 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.
  • testis
  • One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testicle.
  • testosterone
  • A hormone made mainly in the testes (part of the male reproductive system). It is needed to develop and maintain male sex characteristics, such as facial hair, deep voice, and muscle growth. Testosterone may also be made in the laboratory and is used to treat certain medical conditions.
  • tetanus toxoid
  • A substance that is derived from the toxin released by the bacterium that causes the disease tetanus. It is used as a vaccine to prevent tetanus or to help boost the immune response to other vaccines.
  • tethered capsule endoscope
  • A device used to look at tissues in the esophagus. It is a tiny capsule with a laser scanner inside and a very thin cord attached to it. The patient swallows the capsule and the thin cord helps keep the capsule in a specific area in the esophagus. The cord is also used to remove the capsule. Pictures are taken by the laser scanner and sent to a computer for viewing. A tethered capsule endoscope is used to find early cancers of the esophagus and other parts of the body. Also called TCE.
  • tetracycline
  • An antibiotic drug used to treat infection.
  • tetrahydrouridine
  • A substance that makes tumor cells more sensitive to radiation therapy and is being studied in the treatment of cancer. It belongs to the families of drugs called cytidine deaminase inhibitors, multidrug resistance modulators, and radiosensitizers.
  • tetra-O-methyl NDGA
  • A substance being studied in the treatment of cancer. It blocks proteins needed for cancer growth. It is a type of transcriptional inhibitor. Also called EM-1421 and tetra-O-methyl nordihydroguaiaretic acid.
  • tetra-O-methyl nordihydroguaiaretic acid
  • A substance being studied in the treatment of cancer. It blocks proteins needed for cancer growth. It is a type of transcriptional inhibitor. Also called EM-1421 and tetra-O-methyl NDGA.
  • TG4010
  • A substance that is being studied as an anticancer drug.
  • thalamus
  • 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 is used to treat multiple myeloma in patients who have just been diagnosed, and a painful skin disease related to leprosy. It is also being studied in the treatment of other types of cancer. Thalidomide belongs to the family of drugs called angiogenesis inhibitors. Also called Thalomid.
  • Thalomid
  • A drug that is used to treat multiple myeloma in patients who have just been diagnosed, and a painful skin disease related to leprosy. It is also being studied in the treatment of other types of cancer. Thalomid belongs to the family of drugs called angiogenesis inhibitors. Also called thalidomide.
  • 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.
  • Theraloc
  • A monoclonal antibody being studied in the treatment of some types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Theraloc binds the epidermal growth factor receptor (EGFR) and blocks cancer cells that depend on epidermal growth factor for growth. Also called nimotuzumab.
  • therapeutic
  • Having to do with treating disease and helping healing take place.
  • therapeutic angiotensin-(1-7)
  • A substance being studied in the treatment of several types of cancer. Therapeutic angiotensin-(1-7) is a hormone that is made in the laboratory, and helps control blood pressure. It may stop the growth of some types of cancer cells and may stop the growth of blood vessels needed by tumors to grow. It is a type of antiproliferative agent.
  • 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.
  • thermography
  • In medicine, a procedure in which a heat-sensing infrared camera is used to record the surface heat produced by different parts of the body. Abnormal tissue growth can cause temperature changes, which may show up on the thermogram. Thermography may be used to diagnose breast cancer and other tumors.
  • thermotherapy
  • Treatment of disease using heat.
  • thiamine
  • A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Thiamine helps some enzymes work properly, helps break down sugars in the diet, and keeps nerves and the heart healthy. It is found in pork, organ meats, peas, beans, nuts, and whole grains. Thiamine is water-soluble (can dissolve in water) and must be taken in daily. Not enough thiamine can cause a disease called beriberi (a condition marked by heart, nerve, and digestive disorders). Too much thiamine may help cancer cells grow faster. Also called vitamin B1.
  • thiethylperazine
  • A drug used to prevent or reduce nausea and vomiting. It belongs to the families of drugs called antiemetics and phenothiazines.
  • 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.
  • third molar
  • The last tooth to come in at the back of each side of the upper and lower jaws. Third molars usually come in between 17 and 23 years of age, but not everyone has them. Also called wisdom tooth.
  • third-line therapy
  • Treatment that is given when both initial treatment (first-line therapy) and subsequent treatment (second-line therapy) don’t work, or stop working.
  • thoracalgia
  • Chest pain. Also called thoracodynia.
  • thoracentesis
  • Removal of fluid from the pleural cavity through a needle inserted between the ribs.
  • thoracic
  • Having to do with the chest.
  • thoracic surgeon
  • A surgeon who specializes in operating on organs inside the chest, including the heart and lungs.
  • thoracic surgical oncologist
  • A surgeon who specializes in operating on tumors found inside the chest.
  • thoracodynia
  • Chest pain. Also called thoracalgia.
  • thoracoscope
  • A thin tube-like instrument used to examine the inside of the chest. A thoracoscope has a light and a lens for viewing and may have tool to remove tissue.
  • thoracoscopy
  • Examination of the inside of the chest, using a thoracoscope. A thoracoscope 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.
  • thoracotomy
  • An operation to open the chest.
  • throat cancer
  • 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.
  • thrombectomy
  • Surgery to remove a thrombus (blood clot) from a blood vessel.
  • thrombocyte
  • A tiny piece of a cell found in the blood that breaks off from a large cell found in the bone marrow. Thrombocytes help wounds heal and prevent bleeding by forming blood clots. Also called platelet.
  • thrombocytopenia
  • A condition in which there is a lower-than-normal number of platelets in the blood. It may result in easy bruising and excessive bleeding from wounds or bleeding in mucous membranes and other tissues.
  • thrombohemorrhagic event
  • A process that involves either a blood clot or bleeding, such as a heart attack or stroke.
  • thrombolysis
  • The process of breaking up a thrombus (blood clot) that is blocking blood flow. The blood clot may be dissolved using drugs delivered through a catheter (tube) into the clot.
  • thrombophlebitis
  • Inflammation of a vein that occurs when a blood clot forms.
  • thrombopoietin
  • A substance made by the body that helps make blood cells, especially platelets. A form of thrombopoietin made in the laboratory is called recombinant human thrombopoietin and rHu thrombopoietin. Thrombopoietin is being studied as a way to increase the number of platelets in cancer patients receiving chemotherapy. Also called TPO.
  • thrombosis
  • The formation or presence of a thrombus (blood clot) inside a blood vessel.
  • thrombus
  • A blood clot that forms on the wall of a blood vessel or in the heart when blood platelets, proteins, and cells stick together. A thrombus may block the flow of blood.
  • 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 and candidosis.
  • thymic carcinoma
  • A rare type of thymus gland cancer. It usually spreads, has a high risk of recurrence, and has a poor survival rate. Thymic carcinoma is divided into subtypes, depending on the types of cells in which the cancer began. Also called type C thymoma.
  • thymidine
  • A chemical compound found in DNA. Also used as treatment for mucositis.
  • thymidylate synthase inhibitor
  • A protein involved in making and repairing DNA (molecules inside cells that carry genetic information and pass it on from parent to child). High levels of thymidylate synthase may be involved in how certain types of cancer form and respond to treatment.
  • thymine
  • A chemical compound that is used to make one of the building blocks of DNA. It is a type of pyrimidine.
  • Thymitaq
  • A substance that is being studied in the treatment of liver cancer. It belongs to the family of drugs called thymidylate synthase inhibitors. Also called AG337 and nolatrexed.
  • thymocyte
  • A type of immune cell that can attack foreign cells, cancer cells, and cells infected with a virus. Thymocytes can also help control immune responses. A thymocyte is a type of white blood cell. Also called T cell and T lymphocyte.
  • 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.
  • Thyrogen
  • A form of thyroid-stimulating hormone (TSH) that is made in the laboratory. It is used to test for remaining or recurring cancer cells in patients who have been treated for thyroid cancer. Also called thyrotropin alfa.
  • thyroglobulin
  • 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 cancer
  • A gland located beneath the larynx (voice box) that makes thyroid hormone and calcitonin. The thyroid helps regulate growth and metabolism. Also called thyroid gland.
  • thyroid follicular cell
  • A type of cell in the thyroid. Thyroid follicular cells make thyroid hormone.
  • thyroid gland
  • A gland located beneath the larynx (voice box) that makes thyroid hormone and calcitonin. The thyroid gland helps regulate growth and metabolism. Also called thyroid.
  • thyroid hormone
  • A hormone that affects heart rate, blood pressure, body temperature, and weight. Thyroid hormone is made by the thyroid gland and can also be made in the laboratory.
  • thyroid hormone treatment
  • Treatment with thyroid hormone, which is a hormone that affects heart rate, blood pressure, body temperature, and weight.
  • thyroidectomy
  • Surgery to remove part or all of the thyroid.
  • thyroiditis
  • Inflammation of the thyroid gland. Thyroiditis may be an autoimmune disease that affects the thyroid gland over time, causing hypothyroidism (too little thyroid hormone). A temporary form of thyroiditis may also occur after the birth of a baby, or when viral or bacterial infections spread to the thyroid.
  • thyroidologist
  • A medical doctor who specializes in thyroid diseases.
  • thyroid-stimulating hormone
  • A hormone produced by the pituitary gland. Thyroid-stimulating hormone stimulates the release of thyroid hormone from thyroglobulin. It also stimulates the growth of thyroid follicular cells. An abnormal thyroid-stimulating hormone level may mean that the thyroid hormonal regulation system is out of control, usually as a result of a benign condition (hyperthyroidism or hypothyroidism). Also called TSH.
  • thyrotropin alfa
  • A form of thyroid-stimulating hormone (TSH) that is made in the laboratory. It is used to test for remaining or recurring cancer cells in patients who have been treated for thyroid cancer. Also called Thyrogen.
  • thyroxine
  • A hormone that is made by the thyroid gland and contains iodine. Thyroxin increases the rate of chemical reactions in cells and helps control growth and development. Thyroxin can also be made in the laboratory and is used to treat thyroid disorders. Also called L-3,5,5’-tetraiodothyronine, T4, and thyroxine.
  • tiacumicin B
  • A substance being studied in the treatment of diarrhea caused by infection with Clostridium difficile (a type of bacteria that can grow without oxygen) in cancer patients. Tiacumicin B is a type of antibiotic. Also called OPT-80 and PAR-101.
  • tiazofurin
  • An anticancer drug being studied to stop cell growth.
  • tibia
  • The larger of two bones between the knee and ankle. Also called shinbone.
  • ticilimumab
  • A monoclonal antibody being studied in the treatment of melanoma and some other types of cancer. Ticilimumab is made in the laboratory and binds to a protein called CTLA-4 on T cells (a type of white blood cell). CTLA-4 is involved in preventing the activation of T-cells. Ticilimumab may block CTLA-4 and help the immune system kill cancer cells. It is a type of immunomodulatory agent.
  • time to progression
  • A measure of time after a disease is diagnosed (or treated) until the disease starts to get worse. Also called TTP.
  • 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. Also called Sn 117m pentetic acid.
  • 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.
  • tinnitus
  • A disorder in which a person hears noises such as buzzing, ringing, clicking, or the sound of a pulse, when no outside sound is causing them. Tinnitus may have many different causes, and may be a symptom of another disease or condition. It may be caused by certain tumors and anticancer drugs.
  • tinzaparin
  • A drug that is used with another drug, warfarin, to treat blood clots that form deep in the veins and to prevent new blood clots from forming. It is a type of anticoagulant. Also called Innohep and tinzaparin sodium.
  • tinzaparin sodium
  • A drug that is used with another drug, warfarin, to treat blood clots that form deep in the veins and to prevent new blood clots from forming. It is a type of anticoagulant. Also called Innohep and tinzaparin.
  • tipifarnib
  • A substance that is being studied in the treatment of acute myeloid leukemia (AML) and other types of cancer. It belongs to the family of drugs called farnesyltransferase inhibitors. Also called R115777 and Zarnestra.
  • tirapazamine
  • A drug that makes tumor cells more sensitive to radiation therapy.
  • tissue flap reconstruction
  • A group or layer of cells that work together to perform a specific function.
  • tissue plasminogen activator
  • An enzyme made in the body that helps dissolve blood clots. A form of this enzyme is made in the laboratory to treat heart attacks, strokes, and clots in the lungs. It is also being studied in the treatment of cancer. Tissue plasminogen activator is a type of systemic thrombolytic agent. Also called tPA.
  • TLF
  • A drug being studied in the treatment of kidney cancer that has spread. It is also being studied in the treatment of other types of cancer and other conditions. TLF increases the activity of dendritic cells (a type of immune cell) to help kill cancer cells. It is a form of human lactoferrin (a protein found in milk, tears, mucus, bile, and some white blood cells) that is made in the laboratory. TLF is a type of recombinant protein and a type of immunomodulatory protein. Also called talactoferrin and talactoferrin alfa.
  • T-LGL leukemia
  • A type of leukemia in which large T lymphocytes (a type of white blood cell) that contain granules (small particles) are found in the blood. It is a chronic disease that may last for a long time and get worse. Also called T-cell large granular lymphocyte leukemia.
  • TLK286
  • A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called glutathione analogs. Also called Telcyta.
  • T-lymphoblastic lymphoma
  • A type of non-Hodgkin lymphoma in which too many T-cell lymphoblasts (immature white blood cells) are found in the lymph nodes and spleen. It is most common in young men. Also called precursor T-lymphoblastic lymphoma.
  • TM
  • A mental technique used to promote relaxation, reduce stress, and improve quality of life. TM is the registered trademark of the Maharishi Foundation Ltd. Also called Transcendental Meditation.
  • TNF-bound colloidal gold
  • A substance being studied in the treatment of some types of cancer. TNF-bound colloidal gold is made in the laboratory by binding a cancer-killing protein called tumor necrosis factor (TNF) to the surface of very tiny particles of gold. These TNF-gold particles may kill cancer cells without harming healthy tissue. Also called Aurimmune and colloidal gold-bound tumor necrosis factor.
  • TNFerade
  • A protein made by white blood cells in response to an antigen (substance that causes the immune system to make a specific immune response) or infection. TNF can also be made in the laboratory. It may boost a person’s immune response, and also may cause necrosis (cell death) of some types of tumor cells. TNF is being studied in the treatment of some types of cancer. It is a type of cytokine. Also called tumor necrosis factor.
  • TNF-related apoptosis-inducing ligand
  • A cell protein that can attach to certain molecules in some cancer cells and may kill the cells. TNF-related apoptosis-inducing ligand is being studied in the treatment of cancer. Also called Apo-2L, TRAIL, and tumor necrosis factor-related apoptosis-inducing ligand.
  • TNM staging system
  • A system for describing the extent of cancer in a patient’s body. T describes the size of the tumor and whether it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).
  • TNP-470
  • A substance being studied in the treatment of cancer. It may prevent the growth of new blood vessels that tumors need to grow. It is a type of antiangiogenesis agent.
  • tobacco
  • A plant with leaves that have high levels of the addictive chemical nicotine. The leaves may be smoked (in cigarettes, cigars, and pipes), applied to the gums (as dipping and chewing tobacco), or inhaled (as snuff). Tobacco leaves also contain many cancer-causing chemicals, and tobacco use and exposure to secondhand tobacco smoke have been linked to many types of cancer and other diseases. The scientific name is Nicotiana tabacum .
  • tocladesine
  • A substance that has been studied as an anticancer drug. It is an analog of a substance that occurs naturally in the body (cyclic adenosine monophosphate).
  • tomography
  • A series of detailed pictures of areas inside the body. The pictures are created by a computer linked to an x-ray machine.
  • tomotherapy
  • A type of therapy in which radiation is aimed at a tumor from many different directions. The patient lays on a table and is moved through a donut-shaped machine. The radiation source in the machine rotates around the patient in a spiral pattern. Before radiation, a 3-dimensional (3-D) image of the tumor is taken. This helps doctors find the highest dose of radiation that can be used to kill tumor cells while causing less damage to nearby tissue. Tomotherapy is a type of intensity-modulated radiation therapy (IMRT). Also called helical tomotherapy.
  • tonga
  • An herb native to islands in the South Pacific. Substances taken from the root have been used in some cultures to relieve stress, anxiety, tension, sleeplessness, and problems of menopause. Tonga may increase the effect of alcohol and of certain drugs used to treat anxiety and depression. The U.S. Food and Drug Administration advises users that tonga may cause severe liver damage. The scientific name is Piper methysticum . Also called intoxicating pepper, kava kava, rauschpfeffer, and yangona.
  • tongue cancer
  • Cancer that begins in the tongue. When the cancer begins in the front two-thirds of the tongue, it is considered to be a type of oral cavity cancer; when the cancer begins in the back third of the tongue, it is considered to be a type of oropharyngeal or throat cancer.
  • tonsil
  • One of two small masses of lymphoid tissue on either side of the throat.
  • topical
  • On the surface of the body.
  • topical chemotherapy
  • Treatment with anticancer drugs in a lotion or cream applied to the skin.
  • topoisomerase II inhibitor RTA 744
  • A substance being studied in the treatment of adult brain tumors. Topoisomerase II inhibitor RTA 744 crosses the blood-brain barrier and blocks an enzyme needed for cancer growth. It is a type of topoisomerase inhibitor. Also called RTA 744.
  • topoisomerase inhibitor
  • A substance that blocks topoisomerases (enzymes that break and rejoin DNA strands and are needed for cells to divide and grow). Blocking these enzymes may kill cancer cells. Certain topoisomerase inhibitors are being studied in the treatment of cancer.
  • Toposar
  • A drug used to treat testicular and small cell lung cancers. It is also being studied in the treatment of several other types of cancer. Toposar blocks certain enzymes needed for cell division and DNA repair, and it may kill cancer cells. It is a type of podophyllotoxin derivative and a type of topoisomerase inhibitor. Also called etoposide and Vepesid.
  • topotecan
  • A drug used to treat certain types of ovarian cancer, lung cancer, and cervical cancer. Topotecan is a type of topoisomerase inhibitor. Also called Hycamtin and topotecan hydrochloride.
  • topotecan hydrochloride
  • A drug used to treat certain types of ovarian cancer, lung cancer, and cervical cancer. Topotecan hydrochloride is a type of topoisomerase inhibitor. Also called Hycamtin and topotecan.
  • 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.
  • Torisel
  • A drug used to treat advanced renal cell carcinoma (a type of kidney cancer). It is also being studied in the treatment of other types of cancer. Torisel blocks a protein involved in cell division, and may kill cancer cells. It is a type of rapamycin analog and a type of serine/threonine kinase inhibitor. Also called CCI-779 and temsirolimus.
  • tositumomab
  • A monoclonal antibody that is used in the treatment of certain types of non-Hodgkin lymphoma. When tositumomab and iodine I 131 tositumomab (a form of tositumomab that has been chemically changed by adding radioactive iodine) are given together, the combination is called the Bexxar regimen. Also called Bexxar regimen, iodine I 131 tositumomab, and tositumomab and iodine I 131 tositumomab.
  • tositumomab and iodine I 131 tositumomab
  • A combination of monoclonal antibodies used to treat certain types of non-Hodgkin lymphoma. The monoclonal antibody tositumomab is given with iodine I 131 tositumomab (a form of tositumomab that has been chemically changed by adding radioactive iodine). Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Also called Bexxar regimen, iodine I 131 tositumomab, and tositumomab.
  • 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. Also called complete hysterectomy.
  • total laryngectomy
  • An operation to remove all of the larynx (voice box).
  • total mastectomy
  • 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. Part of the stomach, part of the small intestine, the common bile duct, gallbladder, spleen, and nearby lymph nodes are also removed.
  • total parenteral nutrition
  • A form of nutrition that is delivered into a vein. Total parenteral nutrition does not use the digestive system. It may be given to people who are unable to absorb nutrients through the intestinal tract because of vomiting that won't stop, severe diarrhea, or intestinal disease. It may also be given to those undergoing high-dose chemotherapy or radiation and bone marrow transplantation. It is possible to give all of the protein, calories, vitamins and minerals a person needs using total parenteral nutrition. Also called hyperalimentation, parenteral nutrition, and TPN.
  • total PSA
  • The total amount of prostate-specific antigen (PSA) in the blood. It includes the amount of free PSA and the amount of PSA attached to other proteins.
  • total skin electron beam radiation therapy
  • A type of radiation therapy using electrons that is directed at the entire surface of the body. This type of radiation goes into the outer layers of the skin, but does not go deeper into tissues and organs below the skin. Also called TSEB radiation therapy.
  • total-body irradiation
  • Radiation therapy to the entire body. It is usually followed by bone marrow or peripheral stem cell transplantation.
  • Totect
  • A drug used to treat the toxic effects of an anticancer drug that leaks from a vein into surrounding tissue and causes tissue damage. It is also being studied in the treatment of cancer. Totect contains the active ingredient dexrazoxane. It is a type of chemoprotective agent, a type of cardioprotective agent, and a type of topoisomerase inhibitor.
  • totipotent
  • Having to do with cells that are able to develop into any type of cell found in the body.
  • tourniquet
  • A device, such as a strip of cloth or a band of rubber, that is wrapped tightly around a leg or an arm to prevent the flow of blood to the leg or the arm for a period of time. A tourniquet may be used when drawing blood or to stop bleeding after an injury.
  • toxemia
  • Disease caused by the spread of bacteria and their toxins in the bloodstream. Also called blood poisoning and septicemia.
  • toxic
  • Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.
  • toxicity
  • The extent to which something is poisonous or harmful.
  • toxicology
  • The study of poisons, including the source, effect, and treatment of poisoning. It is a branch of pharmacology (the study of drugs).
  • toxin
  • A poison produced by certain animals, plants, or bacteria.
  • TP-38 immunotoxin
  • A substance being studied in the treatment of brain tumors. It combines a protein that binds to certain tumor cells with a bacterial toxin that kills tumor cells.
  • tPA
  • A substance being studied in the treatment of hematologic cancers. It is a type of phorbol ester. Also called 12-O-tetradecanoylphorbol-13-acetate and tetradecanoylphorbol acetate.
  • TPN
  • A form of nutrition that is delivered into a vein. TPN does not use the digestive system. It may be given to people who are unable to absorb nutrients through the intestinal tract because of vomiting that won't stop, severe diarrhea, or intestinal disease. It may also be given to those undergoing high-dose chemotherapy or radiation and bone marrow transplantation. It is possible to give all of the protein, calories, vitamins and minerals a person needs using TPN. Also called hyperalimentation, parenteral nutrition, and total parenteral nutrition.
  • TPO
  • A substance made by the body that helps make blood cells, especially platelets. A form of TPO made in the laboratory is called recombinant human TPO and rHu TPO. TPO is being studied as a way to increase the number of platelets in cancer patients receiving chemotherapy. Also called thrombopoietin.
  • trabectedin
  • A substance that comes from a type of sea squirt and is being studied in the treatment of cancer. It binds to DNA and causes breaks in the DNA. It also blocks the ability of the cell to repair the DNA damage, and may cause cancer cells to die. Trabectedin is also made in the laboratory. It is a type of DNA excision repair inhibitor. Also called ecteinascidin 743 and ET-743.
  • trabecular cancer
  • A rare type of cancer that forms on or just beneath the skin, usually in parts of the body that have been exposed to the sun. It is most common in older people and in people with weakened immune systems. Also called Merkel cell cancer, Merkel cell carcinoma, and neuroendocrine carcinoma of the skin.
  • trace element
  • An element found in very small amounts in a given substance. Organisms need certain trace elements to survive.
  • 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 tracheostomy tube.
  • trachea
  • The airway that leads from the larynx (voice box) to the bronchi (large airways that lead to the lungs). Also called windpipe.
  • trachelectomy
  • Surgery to remove the cervix (the end of the uterus that forms a canal between the uterus and the vagina).The upper part of the vagina and certain pelvic lymph nodes may also be removed. Also called cervicectomy.
  • tracheoesophageal puncture
  • 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
  • Surgery to create an opening (stoma) into the windpipe. The opening itself may also be called a tracheostomy.
  • tracheostomy button
  • 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
  • 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 trach tube.
  • traditional acupuncture
  • A belief or behavior that is passed from generation to generation in a family, a culture, or a religion.
  • traditional Chinese medicine
  • A medical system that has been used for thousands of years to prevent, diagnose, and treat disease. It is based on the belief that qi (the body's vital energy) flows along 20 meridians (channels) throughout the body and keeps a person’s spiritual, emotional, mental, and physical health in balance. Traditional Chinese medicine aims to restore the body’s balance and harmony between the natural opposing forces of yin and yang, which can block qi and cause disease. Traditional Chinese medicine includes acupuncture, diet, herbal therapy, meditation, physical exercise, and massage. Also called Oriental medicine and TCM.
  • TRAIL receptor 1
  • A cell protein that can attach to certain molecules in some cancer cells and may kill the cells. TRAIL is being studied in the treatment of cancer. Also called Apo-2L, TNF-related apoptosis-inducing ligand, and tumor necrosis factor-related apoptosis-inducing ligand.
  • TRAIL receptor 2
  • A protein on the surface of certain cells that binds another protein called TRAIL, which may kill some cancer cells. An increase in the amount or activity of TRAIL receptor 2 on cancer cells may kill more cells. Also called death receptor 5, DR5, TRAIL-R2, and tumor necrosis factor receptor superfamily member 10B.
  • TRAIL-R1
  • A protein on the surface of certain cells that binds another protein called TRAIL, which may kill some cancer cells. An increase in the amount or activity of TRAIL-R1 on cancer cells may kill more cells. Also called death receptor 4, DR4, TRAIL receptor 1, and tumor necrosis factor receptor superfamily member 10A.
  • TRAIL-R2
  • A protein on the surface of certain cells that binds another protein called TRAIL, which may kill some cancer cells. An increase in the amount or activity of TRAIL-R2 on cancer cells may kill more cells. Also called death receptor 5, DR5, TRAIL receptor 2, and tumor necrosis factor receptor superfamily member 10B.
  • tramadol hydrochloride
  • A drug used to treat moderate to severe pain in adults. It binds to opioid receptors in the central nervous system. Tramadol hydrochloride is a type of analgesic agent and a type of opioid. Also called Ultram.
  • tranquilizer
  • A drug that calms and soothes, and reduces stress and tension. Tranquilizers are used to treat anxiety and insomnia.
  • trans fat
  • A type of fat that has certain chemical properties and is usually found in processed foods such as baked goods, snack foods, fried foods, shortening, margarine, and certain vegetable oils. Eating trans fat increases blood cholesterol levels and the risk of heart disease.
  • transabdominal ultrasound
  • A procedure used to examine the organs in the abdomen. An ultrasound transducer (probe) is pressed firmly against the skin of the abdomen. High-energy sound waves from the transducer bounce off tissues and create echoes. The echoes are sent to a computer, which makes a picture called a sonogram. Also called abdominal ultrasound.
  • Transcendental Meditation
  • A mental technique used to promote relaxation, reduce stress, and improve quality of life. Transcendental Meditation is the registered trademark of the Maharishi Foundation Ltd. Also called TM.
  • transcription
  • In biology, the process by which a cell makes an RNA copy of a sequence of DNA that is a gene.
  • transcutaneous electrical nerve stimulation
  • A procedure in which mild electric currents are applied to some areas of the skin. Also called TENS.
  • transdermal
  • Absorbed through the unbroken skin.
  • transfer factor
  • A substance made by some white blood cells. Transfer factor from one person’s white blood cells may be able to cause a specific immune response when injected into the skin of another person.
  • transferrin-CRM107
  • A substance being studied in the treatment of brain tumors. Transferrin-CRM107 is made by linking a diphtheria toxin to transferrin, a protein that binds to fast growing cells, such as tumor cells. The diphtheria toxin then kills the tumor cells. Transferrin-CRM107 is a type of immunotoxin.
  • transformation
  • In medicine, the change that a normal cell undergoes as it becomes malignant.
  • transfusion
  • 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.
  • transient receptor potential cation channel, subfamily V, member 6
  • A protein found in cell membranes that moves calcium into cells. Levels of transient receptor potential cation channel, subfamily V, member 6 are lower than normal in patients who don’t have enough vitamin D. High levels of the protein may be found in breast cancer tissue. It is a type of calcium channel protein. Also called TRPV6.
  • transitional care
  • Support given to patients when they move from one phase of disease or treatment to another, such as from hospital care to home care. It involves helping patients and families with medical, practical, and emotional needs as they adjust to different levels and goals of care.
  • transitional cell cancer
  • A cell that varies in shape depending on whether the tissue is being stretched. Transitional cells may be stretched without breaking apart. They line hollow organs such as the bladder.
  • translation
  • The process of synthesizing an amino acid sequence (protein product) from the messenger RNA code.
  • translational research
  • A term used to describe the process by which the results of research done in the laboratory are used to develop new ways to diagnose and treat disease.
  • translocation
  • A genetic change in which a piece of one chromosome breaks off and attaches to another chromosome. Sometimes pieces from two different chromosomes will trade places with each other. Translocations may lead to medical problems such as leukemia, breast cancer, schizophrenia, muscular dystrophy, and Down syndrome.
  • transperineal biopsy
  • A procedure in which a sample of tissue is removed from the prostate for examination under a microscope. The sample is removed with a thin needle that is inserted through the skin between the scrotum and rectum and into the prostate.
  • transplant surgeon
  • A doctor who specializes in transplantation surgery. The surgeon replaces a patient's organ with an organ from another person.
  • transplantation
  • A surgical procedure in which tissue or an organ is transferred from one area of a person’s body to another area, or from one person (the donor) to another person (the recipient).
  • transrectal biopsy
  • A procedure in which a sample of tissue is removed from the prostate using a thin needle that is inserted through the rectum and into the prostate. Transrectal ultrasound (TRUS) is usually used to guide the needle. The sample is examined under a microscope to see if it contains cancer.
  • transrectal ultrasound
  • A procedure in which a probe that sends out high-energy sound waves is inserted into the rectum. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissue called a sonogram. Transrectal ultrasound is used to look for abnormalities in the rectum and nearby structures, including the prostate. Also called endorectal ultrasound, ERUS, and TRUS.
  • transsphenoidal surgery
  • A type of surgery in which instruments are inserted into part of the brain by going through the nose and the sphenoid bone (a butterfly-shaped bone at the base of the skull). Transsphenoidal surgery is used to remove tumors of the pituitary gland.
  • transurethral biopsy
  • A procedure in which a sample of tissue is removed from the prostate for examination under a microscope. A thin, lighted tube is inserted through the urethra into the prostate, and a small piece of tissue is removed with a cutting loop.
  • transurethral needle ablation
  • A procedure that is used to treat benign prostatic hypertrophy (BPH). A small probe that gives off low-level radiofrequency energy is inserted through the urethra into the prostate. The energy from the probe heats and destroys the abnormal prostate tissue without damaging the urethra. Also called transurethral radiofrequency ablation.
  • transurethral radiofrequency ablation
  • A procedure that is used to treat benign prostatic hypertrophy (BPH). A small probe that gives off low-level radiofrequency energy is inserted through the urethra into the prostate. The energy from the probe heats and destroys the abnormal prostate tissue without damaging the urethra. Also called transurethral needle ablation.
  • transurethral resection of the prostate
  • Surgery performed with a special instrument inserted through the urethra. Also called TUR.
  • transvaginal sonography
  • A procedure used to examine the vagina, uterus, fallopian tubes, ovaries, and bladder. An instrument is inserted into the vagina that causes sound waves to bounce off organs inside the pelvis. These sound waves create echoes that are sent to a computer, which creates a picture called a sonogram. Also called transvaginal ultrasound and TVS.
  • transvaginal ultrasound
  • A procedure used to examine the vagina, uterus, fallopian tubes, ovaries, and bladder. An instrument is inserted into the vagina that causes sound waves to bounce off organs inside the pelvis. These sound waves create echoes that are sent to a computer, which creates a picture called a sonogram. Also called transvaginal sonography and TVS.
  • trastuzumab
  • 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.
  • trauma
  • Injury to the body, or an event that causes long-lasting mental or emotional damage.
  • Traumeel S
  • A substance that contains minerals and extracts of 14 plants, including belladonna, arnica, St. John's wort, and Echinacea. It is being studied as a mouth rinse treatment for oral mucositis (painful mouth sores) caused by cancer therapy. It is known as a homeopathic remedy.
  • Treanda
  • A drug that is used to treat chronic lymphocytic leukemia (CLL) and is being studied in the treatment of other types of cancer. Treanda may damage the DNA in cancer cells and kill them. It is a type of purine analog/alkylator hybrid drug. Also called bendamustine hydrochloride.
  • treatment field
  • In radiation therapy, the place on the body where the radiation beam is aimed.
  • T-regulatory cell
  • A type of immune cell that blocks the actions of some other types of lymphocytes, to keep the immune system from becoming over-active. T-regulatory cells are being studied in the treatment of cancer. A T-regulatory cell is a type of white blood cell and a type of lymphocyte. Also called regulatory T cell, suppressor T cell, and T reg.
  • Trelstar
  • A drug that is used to treat advanced prostate cancer, and is being studied in the treatment of breast cancer. It belongs to the family of hormonal drugs called gonadotropin-releasing hormone analogs. Also called triptorelin.
  • treosulfan
  • A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called alkylating agents.
  • trephine
  • A surgical tool used to cut out circular pieces of bone or other tissue.
  • tretinoin
  • A nutrient that that body needs in small amounts to function and stay healthy. Tretinoin is made in the body from vitamin A and helps cells to grow and develop, especially in the embryo. A form of tretinoin made in the laboratory is put on the skin to treat conditions such as acne and is taken by mouth to treat acute promyelocytic leukemia (a fast-growing cancer in which there are too many immature blood-forming cells in the blood and bone marrow). Tretinoin is being studied in the prevention and treatment of other types of cancer. Also called all-trans retinoic acid, ATRA, retinoic acid, and vitamin A acid.
  • triacetyluridine
  • A substance that is being studied for its ability to protect against the gastrointestinal side effects caused by fluorouracil. It belongs to the family of drugs called cytoprotective agents. Also called PN401.
  • triamcinolone
  • 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.
  • Triapine
  • A substance being studied in the treatment of cancer. It is a type of ribonucleotide reductase inhibitor. Also called 3-aminopyridine-2-carboxaldehyde thiosemicarbazone and 3-AP.
  • 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.
  • TriCor
  • A drug used to treat high levels of cholesterol and triglycerides in the blood. TriCor is being studied in the treatment of advanced cancers in young patients and in the treatment of other conditions. It is a type of antilipidemic agent. Also called fenofibrate and Lofibra.
  • tricyclic antidepressant
  • A type of drug used to treat depression.
  • Trifolium pratense
  • A plant whose flowers have been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called purple clover, red clover, and wild clover.
  • trigeminal nerve
  • The main sensory nerve of the head and face, and the motor nerve of the muscles used in chewing. Also called fifth cranial nerve.
  • trigger point acupuncture
  • In medicine, a specific event that starts a process or that causes a particular outcome. For example, chemotherapy, painful treatments, or the smells, sounds, and sights that go with them may trigger anxiety and fear in a patient who has cancer. In allergies, exposure to mold, pollen or dust may trigger sneezing, watery eyes, and coughing.
  • triiodothyronine
  • A thyroid hormone. Also called T-3.
  • Trilisate
  • A substance used to treat arthritis and relieve pain, inflammation, and fever. It is also being studied in the treatment of acute myeloid leukemia (AML). Trilisate blocks the action of a substance that sends a pain message to the brain. It is a type of nonsteroidal anti-inflammatory drug (NSAID). Also called choline magnesium trisalicylate.
  • 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.
  • trinucleotide repeat
  • Sequences of 3 nucleotides repeated in tandem on the same contiguous section of chromosome. A certain amount of normal (polymorphic) variation in repeat number with no clinical significance commonly occurs between individuals; however, repeat numbers over a certain threshold can, in some cases, lead to adverse effects on the function of the gene, resulting in genetic disease.
  • Triostat
  • A drug that is used to treat certain thyroid (a gland located near the voice box) conditions. It is also being studied in the treatment of thyroid cancer. Triostat is made in the laboratory and is a form of the thyroid hormone triiodthyronine (T3). Also called Cytomel and liothyronine sodium.
  • triple-negative breast cancer
  • Describes breast cancer cells that do not have estrogen receptors, progesterone receptors, or large amounts of HER2/neu protein. Also called ER-negative PR-negative HER2/neu-negative and ER-PR-HER2/neu-.
  • triptorelin
  • A drug that is used to treat advanced prostate cancer, and is being studied in the treatment of breast cancer. It belongs to the family of hormonal drugs called gonadotropin-releasing hormone analogs. Also called Trelstar.
  • Trisenox
  • A drug used to treat acute promyelocytic leukemia (APL) that has not gotten better or that has come back after treatment with other anticancer drugs. It is also being studied in the treatment of other types of cancer. Also called arsenic trioxide.
  • trisomy
  • The presence of an extra chromosome, resulting in a total of three copies of that chromosome instead of the normal 2 copies (e.g., trisomy 21, or Down syndrome).
  • trophoblast
  • A thin layer of cells that helps a developing embryo attach to the wall of the uterus, protects the embryo, and forms a part of the placenta.
  • tropisetron
  • A substance used to treat nausea and vomiting caused by cancer treatment. It is not available in the United States. Tropisetron is a type of serotonin receptor antagonist and a type of antiemetic.
  • troxacitabine
  • A drug being studied for use as an anticancer agent.
  • TRPV6
  • A protein found in cell membranes that moves calcium into cells. Levels of TRPV6 are lower than normal in patients who don’t have enough vitamin D. High levels of the protein may be found in breast cancer tissue. It is a type of calcium channel protein. Also called transient receptor potential cation channel, subfamily V, member 6.
  • true lavender
  • A plant with aromatic leaves and flowers that is a member of the mint family. Oil from the flowers has been used in some cultures to treat certain medical problems, to keep insects away, and to wash in. It is also used in aromatherapy. Perillyl alcohol, a substance found in true lavender, is being studied in cancer prevention and treatment. The scientific name is Lavandula angustifolia . Also called English lavender and lavender.
  • TRUS
  • A procedure in which a probe that sends out high-energy sound waves is inserted into the rectum. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissue called a sonogram. TRUS is used to look for abnormalities in the rectum and nearby structures, including the prostate. Also called endorectal ultrasound, ERUS, and transrectal ultrasound.
  • trust
  • A legal document in which a person states what is to be done with his or her property after death. There are many types of trusts, and a trust may take the place of a will.
  • TSEB radiation therapy
  • A type of radiation therapy using electrons that is directed at the entire surface of the body. This type of radiation goes into the outer layers of the skin, but does not go deeper into tissues and organs below the skin. Also called total skin electron beam radiation therapy.
  • 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). Also called thyroid-stimulating hormone.
  • TTI-237
  • A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called mitotic inhibitors.
  • tubal ligation
  • An operation to tie the fallopian tubes closed. This procedure prevents pregnancy by blocking the passage of eggs from the ovaries to the uterus.
  • tubefeeding
  • A type of enteral nutrition (nutrition that is delivered into the digestive system in a liquid form). For tubefeeding, a small tube may be placed through the nose into the stomach or the small intestine. Sometimes it is surgically placed into the stomach or the intestinal tract through an opening made on the outside of the abdomen, depending on how long it will be used. People who are unable to meet their needs with food and beverages alone, and who do not have vomiting or uncontrollable diarrhea may be given tubefeedings. Tubefeeding can be used to add to what a person is able to eat or can be the only source of nutrition.
  • tuberculosis
  • 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.
  • tuberous sclerosis
  • A genetic disorder in which benign (not cancer) tumors form in the kidneys, brain, eyes, heart, lungs, and skin. This disease can cause seizures, mental disabilities, and different types of skin lesions.
  • tubulin
  • One of a group of proteins found in high levels in the cell cytoplasm (fluid inside a cell but outside the cell's nucleus). Tubulins are the building blocks of microtubules (narrow, hollow tubes inside a cell), which are involved in cell division and cell movement. Certain anticancer drugs bind to and block the formation or function of tubulins, which may block cell division.
  • tubulovillous adenoma
  • A type of polyp that grows in the colon and other places in the gastrointestinal tract and sometimes in other parts of the body. These adenomas may become malignant (cancer).
  • tui na
  • Chinese massage that uses kneading, pressing, rolling, shaking, and stretching of the body. Tui na is thought to regulate qi (vital energy) and blood flow, and improve the function of tendons, bones, and joints.
  • tumescent mastectomy
  • A type of surgery to remove the breast. The breast is injected with a liquid mixture of salts and small amounts of two drugs. These drugs are lidocaine, to numb the area, and epinephrine, to narrow blood vessels and reduce bleeding. Tumescent mastectomy is usually used to treat breast cancer in elderly patients.
  • tumor antigen vaccine
  • 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.
  • tumor board review
  • A treatment planning approach in which a number of doctors who are experts in different specialties (disciplines) review and discuss the medical condition and treatment options of a patient. In cancer treatment, a tumor board review may include that of a medical oncologist (who provides cancer treatment with drugs), a surgical oncologist (who provides cancer treatment with surgery), and a radiation oncologist (who provides cancer treatment with radiation). Also called multidisciplinary opinion.
  • tumor burden
  • Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor load.
  • tumor debulking
  • Surgical removal of as much of a tumor as possible. Tumor debulking may increase the chance that chemotherapy or radiation therapy will kill all the tumor cells. It may also be done to relieve symptoms or help the patient live longer. Also called debulking.
  • tumor infiltrating lymphocyte
  • A white blood cell that has left the bloodstream and migrated into a tumor.
  • tumor initiation
  • A process in which normal cells are changed so that they are able to form tumors. Substances that cause cancer can be tumor initiators.
  • tumor load
  • Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor burden.
  • tumor lysis syndrome
  • A condition that can occur after treatment of a fast-growing cancer, especially certain leukemias and lymphomas (cancers of the blood). As tumor cells die, they break apart and release their contents into the blood. This causes a change in certain chemicals in the blood, which may cause damage to organs, including the kidneys, heart, and liver.
  • tumor marker
  • A substance that may be found in tumor tissue or released from a tumor into the blood or other body fluids. A high level of a tumor marker may mean that a certain type of cancer is in the body. Examples of tumor markers include CA 125 (in ovarian cancer), CA 15-3 (in breast cancer), CEA (in ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (in prostate cancer).
  • tumor microenvironment
  • The normal cells, molecules, and blood vessels that surround and feed a tumor cell. A tumor can change its microenvironment, and the microenvironment can affect how a tumor grows and spreads.
  • tumor model
  • Cells, tissues, or animals used to study the development and progression of cancer, and to test new treatments before they are given to humans. Animals with transplanted human tumors or other tissues are called xenograft models.
  • tumor necrosis factor
  • A protein made by white blood cells in response to an antigen (substance that causes the immune system to make a specific immune response) or infection. Tumor necrosis factor can also be made in the laboratory. It may boost a person’s immune response, and also may cause necrosis (cell death) of some types of tumor cells. Tumor necrosis factor is being studied in the treatment of some types of cancer. It is a type of cytokine. Also called TNF.
  • tumor necrosis factor receptor superfamily member 10A
  • A protein on the surface of certain cells that binds another protein called TRAIL, which may kill some cancer cells. An increase in the amount or activity of tumor necrosis factor receptor superfamily member 10A on cancer cells may kill more cells. Also called death receptor 4, DR4, TRAIL receptor 1, and TRAIL-R1.
  • tumor necrosis factor receptor superfamily member 10B
  • A protein on the surface of certain cells that binds another protein called TRAIL, which may kill some cancer cells. An increase in the amount or activity of tumor necrosis factor receptor superfamily member 10B on cancer cells may kill more cells. Also called death receptor 5, DR5, TRAIL receptor 2, and TRAIL-R2.
  • tumor necrosis factor-related apoptosis-inducing ligand
  • A cell protein that can attach to certain molecules in some cancer cells and may kill the cells. Tumor necrosis factor-related apoptosis-inducing ligand is being studied in the treatment of cancer. Also called Apo-2L, TNF-related apoptosis-inducing ligand, and TRAIL.
  • tumor promotion
  • A process in which existing tumors are stimulated to grow. Tumor promoters are not able to cause tumors to form.
  • tumor suppressor gene
  • 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.
  • tumor vasculature–targeted tumor necrosis factor alpha
  • A substance being studied in the treatment of cancer. It is made by linking tumor necrosis factor (TNF) to a peptide. The peptide binds to tumor blood vessels, and TNF damages them. It is a type of biological response modifier. Also called NGR-TNF.
  • tumor volume
  • The size of a cancer measured by the amount of space taken up by the tumor. For example, the tumor volume of prostate cancer is the percentage of the prostate taken up by the tumor.
  • 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.
  • Turkish rhubarb
  • Surgery performed with a special instrument inserted through the urethra. Also called transurethral resection.
  • turmeric
  • An East Indian plant that is a member of the ginger family and is used as a spice and food color. The underground stems are used in some cultures to treat certain stomach problems. The substance in turmeric that gives it a yellow color (curcumin) is being studied in the treatment of cancer, Alzheimer disease, cystic fibrosis, and psoriasis. The scientific name is Curcuma longa . Also called Indian saffron and jiang huang.
  • TURP
  • Surgery 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, ovaries, and bladder. An instrument is inserted into the vagina that causes sound waves to bounce off organs inside the pelvis. These sound waves create echoes that are sent to a computer, which creates a picture called a sonogram. Also called transvaginal sonography and transvaginal ultrasound.
  • twelve-step program
  • A program to help people recover from substance abuse, emotional disorders, or addictions. The twelve steps come from an organization called Alcoholics Anonymous (AA) and are changed for each specific condition.
  • Tykerb
  • A drug used with another anticancer drug to treat breast cancer that is HER2 positive and has advanced or metastasized (spread to other parts of the body) after treatment with other drugs. Tykerb is also being studied in the treatment of other types of cancer. It is a type of ErbB-2 and EGFR dual tyrosine kinase inhibitor. Also called GW572016, lapatinib, and lapatinib ditosylate.
  • tympanites
  • Swelling of the abdomen caused by gas in the intestines or peritoneal cavity. Also called meteorism.
  • type 3 serotonin receptor antagonist
  • A type of drug used to treat certain types of irritable bowel syndrome and relieve nausea and vomiting. It is a type of antiemetic. Also called 5-HT3 receptor antagonist and 5-hydroxytryptamine 3 receptor antagonist.
  • type C thymoma
  • A rare type of thymus gland cancer. It usually spreads, has a high risk of recurrence, and has a poor survival rate. Thymic carcinoma is divided into subtypes, depending on the types of cells in which the cancer began. Also called thymic carcinoma.
  • tyrosinase peptide
  • 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.
  • tyrosine kinase inhibitor
  • A drug that interferes with cell communication and growth and may prevent tumor growth. Some tyrosine kinase inhibitors are used to treat cancer.
  • tyrosine kinase inhibitor BIBF 1120
  • A substance being studied in the treatment of some types of cancer. Tyrosine kinase inhibitor BIBF 1120 blocks enzymes needed for cells to grow, and may prevent the growth of new blood vessels that tumors need to grow. It is a type of tyrosine kinase inhibitor and a type of antiangiogenesis agent. Also called BIBF 1120.
  • TZT-1027
  • A substance being studied in the treatment of cancer. It is a type of tubulin inhibitor. Also called soblidotin.
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