chemoprevention

chemotherapy Of or pertaining to treatment with drugs to kill cancer cells. Most anticancer drugs are injected into a vein, but some are given by mouth. Chemotherapy is usually systemic treatment, meaning that the drugs flow through the bloodstream to nearly every part of the body. Chemotherapy is generally given in cycles: A treatment period is followed by a recovery period, another treatment period, and so on. The side effects of chemotherapy depend mainly on the drugs and doses the patient receives. Generally, anticancer drugs affect cells that divide rapidly, including blood cells, which fight infection, help the blood to clot, and carry oxygen to all parts of the body. When white blood cells are affected by anticancer drugs, patients are more likely to develop infections. When red blood cells are affected, they may have decreased energy. Cells that line the digestive tract also divide rapidly, so chemotherapy can cause loss of appetite, nausea and vomiting, hair loss or thinning, and mouth sores. For some patients, medicines can be prescribed to help with side effects, especially with nausea and vomiting. Usually these side effects gradually go away during the recovery period or after treatment stops. In some men and women, chemotherapy drugs may result in temporary or permanent loss of the ability to have children. For men, sperm banking before treatment may be considered; women may choose to have eggs extracted and stored. Women’s menstrual periods may stop, and women may have hot flashes and vaginal dryness due to induced menopause. In some cases, bone marrow transplantation and peripheral stemcell support are used to replace bone marrow tissue that has been destroyed by the effects of chemotherapy. See also adjuvant chemotherapy; cancer.