Chemotherapy

Chemotherapy is the treatment of cancer by drugs which kill or slow the growth of the cancer cells.

Chemotherapeutic medications are specific drugs which have toxic effects on cells. They try to exploit the unique characteristics of cancer cells to do the most damage to these diseased cells while leaving normal, healthy cells alone. While there are many different types of chemotherapeutic drugs with many different mechanisms of action, most commonly these drugs are most active against cells that grow and divide rapidly. Because cancer cells typically grow faster than normal cells in the body, they are particularly susceptible to the effects of these drugs.

However, some normal cells can be damaged by chemotherapeutic drugs as well. Cells which normally divide quickly are particularly susceptible to damage. This includes cells in the skin, hair follicles, the lining of the intestines, and the bone marrow (which produces blood cells). The toxic effects on these and other normal tissues are considered side effects of treatment with chemotherapeutic drugs. However, some amount of side effects is often tolerated if the medication helps to control the cancer. Specific side effects, their frequency and their severity all vary considerably from medication to medication and from patient to patient.

There are dozens or even hundreds of different chemo medications. Treatment of any specific type of cancer with these drugs may utilize only one drug at a time or some combination, or "cocktail", of chemotherapy drugs. The specific types of drugs used depends on the type of cancer and the treatment protocol being followed, which varies considerably.

Treatment protocols can vary widely. Some medications are only given in the hospital by intravenous (IV) infusion of the drug while others can be taken at home and are taken by mouth. Some are given in short, high-dose treatments while others are given chronically, over a long period of time.

Response of a cancer to chemotherapy treatment can vary widely as well. While some cancers are very susceptible to appropriate drug treatments, and can even cure the cancer, others are very resistant and are not well treated by these means.