Several types of cancer, including some breast and prostate cancers, can only grow and spread in the presence of natural chemicals in the body called hormones. Hormone therapy fights cancer by changing the amounts of hormones in the body, and is used to treat cancers of the prostate, breast and reproductive system. For example, tamoxifen (Nolvadex) is an anti-estrogen drug used to treat some hormone-responsive breast cancers.
Hormone therapy does have potential side effects, but most side effects go away once treatment is finished. The side effects depend on the drug and affect men and women differently. Refer to individual cancer types on the Conditions page for more information about hormone therapy and specific side effects, such as infertility, heart problems (from radiation to the chest), gastrointestinal problems (from radiation to the abdominal area), lung fibrosis (scarring or thickening of the lung tissue), neurologic problems, thyroid problems or osteoporosis. Also, people who have had previous radiation to the chest should be aware that they are at higher risk of developing breast and lung cancers. Today, most people who receive radiation therapy now receive smaller doses than what was given in years past. Each individual considering radiation therapy should discuss the risks versus benefits of the treatment with his or her doctor.