Side effects include life-threatening allergic reactions, loss of appetite, nausea, vomiting, fever, and high blood sugar levels. Hormone therapies raise or lower levels of certain hormones to limit the growth of cancers that either depend on those hormones or are inhibited by them. For instance, some breast cancers need estrogen to grow. The antiestrogen drug tamoxifen blocks the effects of estrogen and may shrink the cancer. Similarly, prostate cancer may be inhibited by estrogen or antitestosterone drugs.
Side effects vary, depending on the hormone taken.
Giving estrogen to a man may have feminizing effects, such as breast enlargement. Giving antiestrogen drugs to a woman may cause hot flashes and irregular menstrual periods. Interferon, the first effective biologic response modifier, is now commonly used to treat Kaposi's sarcoma and multiple myeloma. A treatment that uses antibodies to tumor cells, which are labeled with either a radioactive material or a toxin, has demonstrated effectiveness in treating some lymphomas. Surgery or radiation therapy treats cancer that is confined locally, while chemotherapy kills cancer cells that have escaped beyond the local region.