Glossary of Medical Terms

A substance made up of elements, such as hydrogen or sodium.

Too much or too little of any substance that helps the body work the way it should. A chemical imbalance may be caused by certain tumors and can cause changes in behavior or emotion.

A procedure used to improve the way certain skin problems look. These problems include acne scars, wrinkles, or skin changes caused by long-term sun exposure. A chemical solution is put on the skin to dissolve the top layers of skin cells. Also called chemabrasion and chemexfoliation.

A term commonly used to describe thinking and memory problems that a patient with cancer may have before, during, or after cancer treatment. Signs and symptoms of chemo brain include disorganized behavior or thinking, confusion, memory loss, and trouble concentrating, paying attention, learning, and making decisions. Chemo brain may be caused by the cancer itself (such as brain tumors) or by cancer treatment, such as chemotherapy and other anticancer drugs, radiation therapy, hormone therapy, and surgery. It may also be caused by conditions related to cancer treatment, such as anemia, fatigue, infection, pain, hormone changes, sleep problems, nutrition problems, stress, anxiety, and depression. Chemo brain may last for a short time or for many years.

A procedure in which the blood supply to a tumor is blocked after anticancer drugs are given in blood vessels near the tumor. Sometimes, the anticancer drugs are attached to small beads that are injected into an artery that feeds the tumor. The beads block blood flow to the tumor as they release the drug. This allows a higher amount of drug to reach the tumor for a longer period of time, which may kill more cancer cells. It also causes fewer side effects because very little of the drug reaches other parts of the body. Chemoembolization is used to treat liver cancer. Also called TACE and transarterial chemoembolization.

Chemotherapy combined with immunotherapy. Chemotherapy uses different drugs to kill or slow the growth of cancer cells; immunotherapy uses treatments to stimulate or restore the ability of the immune system to fight cancer.

One of a large group of proteins that is made by certain immune cells and other cells in the body. Chemokines play an important role in the body’s immune response. They stimulate the movement of certain types of white blood cells and attract them to areas of inflammation to help the body fight infections, inflammatory conditions, and other diseases. They also help keep the immune system working the way it should. A chemokine is a type of cytokine.

The use of drugs, vitamins, or other agents to try to reduce the risk of, or delay the development or recurrence of, cancer.

In cancer prevention, a clinical trial that studies whether taking certain medicines, vitamins, minerals, or food supplements can prevent cancer. Also called agent study.

A type of drug that helps protect healthy tissue from some of the side effects caused by certain anticancer drugs. For example, in patients receiving certain anticancer drugs, amifostine helps protect the kidneys, mesna helps protect the bladder, and dexrazoxane (Zinecard) helps reduce heart damage.