Breast Cancer Risk Reduction Clinical Practice Guidelines in Oncology.

Breast cancer risk factor analysis allows the identification of women at very high risk for the future development of breast cancer. Many of the known risk factors are either not modifiable or are not reasonably modifiable because of social implications or other potential health benefits (eg, those associated with hormone replacement therapy). Thus, effective strategies to decrease the risk of breast cancer are needed. The recent demonstration that the use of tamoxifen for 5 years decreases the future risk of breast cancer by approximately 49% provides the opportunity for a risk-reduction intervention. Women taking tamoxifen must be monitored for the occurrence of well-defined toxicities, including hot flashes and, more rarely, endometrial carcinoma, thromboembolic disease, and cataract formation. Strategies are available for the management of tamoxifen toxicity. In special circumstances, such as in carriers of BRCA1 or BRCA2 mutations, the risk of future breast cancer is very high, and the performance of a bilateral prophylactic mastectomy may be considered. Women considering bilateral prophylactic mastectomy should undergo multidisciplinary consultation so that they may make a fully informed decision. The panel strongly encourages patients and health care providers to participate in clinical trials to test new strategies for decreasing the risk of breast cancer. Only through the accumulated experience gained from well-designed, prospective clinical trials will additional advances in the reduction of breast cancer risk be realized.