Breast cancer chemoprevention

Chemoprevention of breast cancer is a rapidly growing field. Chemoprevention was initiated with the development of the antiestrogen tamoxifen. A major clinical trial in the United States found that tamoxifen reduced the incidence of breast cancer by almost 50% in women at an increased risk for the disease. Although two European trials did not confirm these findings, the Food and Drug Administration found the American studies significant enough to approve tamoxifen for the delaying of breast cancer in women at high risk for the disease. However, adverse effects associated with tamoxifen include a minimally increased rate of endometrial cancer, cataracts, and strokes. Newer classes of antiestrogens, called selective estrogen receptor modulators (SERMs), are being investigated as potential chemopreventive agents. These SERMS, such as raloxifene, will hopefully provide some of the benefits of estrogen without its inherent risks. In addition, naturally occurring compounds and their analogues are also under investigation.