Breast cancer risk assessment and risk reduction.

Until recently, the primary message of breast health awareness programs was that early detection is a woman's best protection against breast cancer, because there was no way to prevent it. Currently, however, tamoxifen is approved for chemoprevention of breast cancer in high-risk women, and studies are underway evaluating other medications that may decrease breast cancer risk. Data have also become available regarding the efficacy of surgical strategies to reduce breast cancer risk. Any prevention method, however, will have associated risk of complications or adverse effects, and determining the net risk/benefit ratio depends on the ability to accurately quantify a woman's baseline likelihood of developing breast cancer. This article reviews available methods for assessing and reducing breast cancer risk.