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Glossary of Cancer Terms

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

ubiquinone A substance found in most tissues in the body and in many foods. It can also be made in the laboratory. It is used by the body to produce energy for cells, and as an antioxidant. It is being studied in the treatment of cancer and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, Q10, CoQ10 and vitamin Q10.

UCN-01 An anticancer drug that belongs to the family of drugs called staurosporine analogs.

UGT1A1 A substance that is being studied as a treatment for cancer. It is an enzyme produced by the liver and intestine.

ulcer A break on the skin, in the lining of an organ or on the surface of a tissue. An ulcer forms when the surface cells become inflamed, die, and are shed. Ulcers may be linked to cancer and other diseases.

ulceration The formation of a break on the skin or on the surface of an organ. An ulcer forms when the surface cells die and are cast off. Ulcers may be associated with cancer and other diseases.

ulcerative colitis Chronic inflammation of the colon that produces ulcers in its lining. This condition is marked by abdominal pain, cramps, and loose discharges of pus, blood, and mucus from the bowel.

Ulmus fulva (Ulmus rubra) The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called slippery elm, gray elm, Indian elm, red elm, sweet elm and Ulmus rubra.

Ulmus rubra (Ulmus fulva) The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called slippery elm, gray elm, Indian elm, red elm, sweet elm and Ulmus fulva.

ultrasonogram A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called a sonogram.

ultrasonography A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasound.

ultrasound A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasonography.

ultrasound energy A form of therapy being studied as an anticancer treatment. Intensified ultrasound energy can be directed at cancer cells to heat them and kill them.

ultrasound transducer A device that produces sound waves that bounce off body tissues and make echoes. The transducer also receives the echoes and sends them to a computer that uses them to create a picture called a sonogram. Transducers (probes) come in different shapes and sizes for use in making pictures of different parts of the body. The transducer may be passed over the surface of the body or inserted into an opening such as the rectum or vagina.

ultrasound-guided biopsy A biopsy procedure that uses an ultrasound imaging device to find an abnormal area of tissue and guide its removal for examination under a microscope.

ultraviolet radiation (UV radiation) Invisible rays that are part of the energy that comes from the sun. UV radiation also comes from sun lamps and tanning beds. UV radiation can damage the skin and cause melanoma and other types of skin cancer. UV radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB rays. UVB rays are more likely than UVA rays to cause sunburn, but UVA rays pass deeper into the skin.

Scientists have long thought that UVB radiation can cause melanoma and other types of skin cancer. They now think that UVA radiation also may add to skin damage that can lead to skin cancer and cause premature aging. For this reason, skin specialists recommend that people use sunscreens that reflect, absorb, or scatter both kinds of UV radiation. Also called UV radiation.

ultraviolet radiation therapy A form of radiation used in the treatment of cancer.

umbilical cord blood Blood from the umbilical cord of a newborn baby. This blood contains high concentrations of stem cells (cells from which all blood cells develop).

umbilical cord blood transplantation The injection of umbilical cord blood to restore an individual's own blood production system suppressed by anticancer drugs, radiation therapy or both. It is being studied in the treatment of cancer and severe blood disorders such as aplastic anemia. Cord blood contains high concentrations of stem cells needed to produce new blood cells.

uncontrolled study A clinical study that lacks a comparison (i.e., a control) group.

unconventional cancer treatments Approaches that use substances or methods of treating cancer that have not been shown to be effective by accepted scientific methods, such as carefully designed clinical trials.

underactive thyroid Too little thyroid hormone. Symptoms include weight gain, constipation, dry skin and sensitivity to the cold. Also called hypothyroidism.

undescended testicles A condition in which one or both testicles fail to move from the abdomen, where they develop before birth, into the scrotum. Undescended testicles may increase the risk for development of testicular cancer. Also called cryptorchidism.

undifferentiated A term used to describe cells or tissues that do not have specialized ("mature") structures or functions. Undifferentiated cancer cells often grow and spread quickly.

unguent A substance used on the skin to soothe or heal wounds, burns, rashes, scrapes, or other skin problems. Also called ointment.

unilateral Having to do with one side of the body.

unilateral salpingo-oophorectomy Surgery to remove the ovary and fallopian tube on one side of the body.

unresectable Unable to be removed with surgery.

unresectable gallbladder cancer Cancer that has spread to the tissues around the gallbladder (such as the liver, stomach, pancreas, intestine or lymph nodes in the area) and cannot be surgically removed.

unresected Describes an organ, tissue or cancer that has not been either partly or completely removed by surgery.

unsealed internal radiation therapy Radiation therapy given by injecting a radioactive substance into the bloodstream or a body cavity, or by swallowing it. This substance is not sealed in a container.

upper endoscopy Examination of the inside of the stomach using an endoscope, passed through the mouth and esophagus. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called gastroscopy.

upper GI series A series of X-rays of the esophagus. The X-ray pictures are taken after the person drinks a solution that contains barium. The barium coats and outlines the esophagus on the X-ray. Also called esophagram and barium swallow.

urachus A fibrous cord that connects the urinary bladder to the umbilicus (navel). The urachus is formed as the allantoic stalk during fetal development and lasts through life. Also called median umbilical ligament.

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

urea nitrogen A chemical in the blood produced by the breakdown of protein. Urea nitrogen is removed from the blood by the kidneys. Blood urea nitrogen (BUN) tests are sometimes done to see how well the kidneys are working.

ureter The tube that carries urine from the kidney to the bladder.

ureteronephrectomy Surgery to remove a kidney and its ureter. Also called nephroureterectomy.

ureteroscopy Examination of the inside of the kidney and ureter, using a ureteroscope. A ureteroscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. The ureteroscope is passed through the urethra into the bladder, ureter, and renal pelvis (part of the kidney that collects, holds, and drains urine).

urethra The tube through which urine leaves the body. It empties urine from the bladder.

urethral cancer A rare cancer that forms in tissues of the urethra (the tube through which urine empties the bladder and leaves the body). Types of urethral cancer include transitional cell carcinoma (cancer that begins in cells that can change shape and stretch without breaking apart), squamous cell carcinoma (cancer that begins in flat cells lining the urethra), and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids).

uric acid A waste product left over from normal chemical processes in the body and found in the urine and blood. Abnormal buildup of uric acid in the body may cause a condition called gout. Increased levels of uric acid in the blood and urine can be a side effect of chemotherapy or radiation therapy.

urinalysis A test that determines the content of the urine.

urinary Having to do with urine or the organs of the body that produce and get rid of urine.

urinary diversion A surgical procedure to make a new way for urine to leave the body. It may involve redirecting urine into the colon, using catheters to drain the bladder, or making an opening in the abdomen and collecting urine in a bag outside the body.

urinary incontinence Inability to hold urine in the bladder.

urinary tract The organs of the body that produce and discharge urine. These include the kidneys, ureters, bladder and urethra.

urine Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.

urine cytology Tests performed on cells in urine to detect disease.

urokinase A drug that dissolves blood clots or prevents them from forming.

urologic oncologist A doctor who specializes in treating cancers of the urinary system.

urologist A doctor who specializes in diseases of the urinary organs in females and the urinary and sex organs in males.

urostomy An operation to create an opening from inside the body to the outside, making a new way to pass urine.

urothelium The lining of the urinary tract, including the renal pelvis, ureters, bladder and urethra.

ursodiol A drug that is used to dissolve gallstones in people who can’t have surgery to remove them. It is also being studied in the prevention of colorectal cancer. Ursodiol belongs to the family of drugs called anticholelithics.

uterine cancer Cancer that forms in tissues of the uterus (small, hollow, pear-shaped organ in a woman's pelvis in which a baby grows). Two types of uterine cancer are endometrial cancer (cancer that begins in cells lining the uterus) and uterine sarcoma (a rare cancer that begins in muscle or other tissues in the uterus).

uterine sarcoma A rare type of uterine cancer that forms in muscle or other tissues of the uterus (the small, hollow, pear-shaped organ in a woman's pelvis in which a baby grows). It usually occurs after menopause. The two main types are leiomyosarcoma (cancer that begins in smooth muscle cells) and endometrial stromal sarcoma (cancer that begins in connective tissue cells).

uterus The small, hollow, pear-shaped organ in a woman's pelvis. This is the organ in which a baby grows. Also called the womb.

UV radiation Ultraviolet radiation. Invisible rays that are part of the energy that comes from the sun. UV radiation also comes from sun lamps and tanning beds. UV radiation can damage the skin and cause melanoma and other types of skin cancer. UV radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB rays. UVB rays are more likely than UVA rays to cause sunburn, but UVA rays pass deeper into the skin.

Scientists have long thought that UVB radiation can cause melanoma and other types of skin cancer. They now think that UVA radiation also may add to skin damage that can lead to skin cancer and cause premature aging. For this reason, skin specialists recommend that people use sunscreens that reflect, absorb, or scatter both kinds of UV radiation. Also called ultraviolet radiation.

UVA radiation A type of ultraviolet (UV) radiation. UV rays are invisible rays that are part of the energy that comes from the sun. UVA radiation also comes from sun lamps and tanning beds. Scientists think that UVA radiation may cause skin damage that can lead to skin cancer and premature aging. For this reason, skin specialists recommend that people use sunscreens that reflect, absorb, or scatter ultraviolet radiation.

UVB radiation A type of ultraviolet (UV) radiation. UV rays are invisible rays that are part of the energy that comes from the sun. UVB radiation causes sunburn, and scientists have long thought that it can cause melanoma and other types of skin cancer. Skin specialists recommend that people use sunscreens that reflect, absorb, or scatter ultraviolet radiation.

uvula The soft flap of tissue that hangs down at the back of the mouth (at the edge of the soft palate). Also called palatine uvula.

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