Glossary of Medical Terms

A drug used to treat adults and children aged 2 years and older with severe or life-threatening cytokine release syndrome caused by a type of immunotherapy called chimeric antigen receptor (CAR) T-cell therapy. Actemra is also used to treat certain types of arthritis and a condition that causes inflammation of the lining of the arteries. It is also being studied in the treatment of other conditions. Actemra binds to receptors for a protein called interleukin-6 (IL-6), which is made by white blood cells and other cells in the body. This may help lower the body’s immune response and reduce inflammation. Actemra is a type of monoclonal antibody. Also called tocilizumab.

A hormone made in the pituitary gland. ACTH acts on the outer part of the adrenal gland to control its release of corticosteroid hormones. More ACTH is made during times of stress. Also called adrenocorticotropic hormone and corticotropin.

A rare tumor that makes the hormone adrenocorticotropin (ACTH), which causes the adrenal glands to make too much cortisol. ACTHomas can lead to Cushing syndrome. Signs and symptoms of ACTHomas and Cushing syndrome include a round face, thin arms and legs, severe fatigue and muscle weakness, high blood pressure, high blood sugar, purple or pink stretch marks on the skin, and weight gain, especially in the abdomen. ACTHomas usually form in the pituitary gland or in the islet cells of the pancreas, but they may also form in other organs, including the lung, thyroid, and thymus. ACTHomas may be benign (not cancer) or malignant (cancer). Also called adrenocorticotropic-secreting tumor.

A drug put on the skin to treat growths caused by sun exposure. A form of Actinex that is taken by mouth is being studied in the treatment of prostate cancer. Actinex is an antioxidant, and it may block certain enzymes needed for tumor growth. Also called masoprocol, NDGA, and nordihydroguaiaretic acid.

A thick, scaly patch of skin that may become cancer. It usually forms on areas exposed to the sun, such as the face, scalp, back of the hands, or chest. It is most common in people with fair skin. Also called senile keratosis and solar keratosis.

A drug used to treat Ewing sarcoma, gestational trophoblastic tumor, Wilms tumor, and certain types of testicular cancer. It is also used to treat rhabdomyosarcoma in children. It is being studied in the treatment of other types of cancer. Actinomycin D comes from the bacterium Streptomyces parvulus. It damages the cell’s DNA and may kill cancer cells. It is a type of anticancer antibiotic. Also called Cosmegen and dactinomycin.

In cancer prevention clinical trials, a study that focuses on finding out whether actions people take can prevent cancer.

A form of tissue plasminogen activator that is made in the laboratory. It helps dissolve blood clots and is used to treat heart attacks, strokes, and clots in the lungs. It is also being studied in the treatment of cancer. It is a type of systemic thrombolytic agent. Also called Alteplase, r-tPA, and recombinant tissue plasminogen activator.

In biology, to stimulate a cell in a resting state to become active. This causes biochemical and functional changes in the activated cell.

A treatment plan that involves closely watching a patient’s condition but not giving any treatment unless there are changes in test results that show the condition is getting worse. Active monitoring may be used to avoid or delay the need for treatments such as radiation therapy or surgery, which can cause side effects or other problems. During active monitoring, certain exams and tests are done on a regular schedule. It may be used in the treatment of certain types of cancer, such as prostate cancer, urethral cancer, and intraocular (eye) melanoma. Active monitoring is a type of expectant management. Also called active surveillance.