Breast Cancer Prevention: Current Approaches and Future Directions.

The topic of breast cancer prevention is very broad. All aspects of the topic, therefore, cannot be adequately covered in a single review. The objective of this review is to discuss strategies in current use to prevent breast cancer, as well as potential approaches that could be used in the future. This review does not discuss early detection strategies for breast cancer, including breast cancer screening. The breast is the most common site among women worldwide of noncutaneous cancer. Many clinical and genetic factors have been found to increase a woman's risk of developing the disease. Current strategies to decrease a woman's risk of developing breast cancer include primary prevention, such as avoiding tobacco, exogenous hormone use and excess exposure to ionizing radiation, maintaining a normal weight, exercise, breastfeeding, eating a healthy diet and minimizing alcohol intake. Chemoprevention medications are available for those at high risk, though they are underutilized in eligible women. Mastectomy and/or bilateral oophorectomy are reasonable strategies for women who have deleterious mutations in genes that dramatically increase the risk of developing cancer in either breast. There are a variety of strategies in development for the prevention of breast cancer. Personalized approaches to prevent breast cancer that are being developed focus on advances in precision medicine, knowledge of the immune system and the tumor microenvironment and their role in cancer development. Advances in our understanding of how breast cancer develops are allowing investigators to specifically target populations who are most likely to benefit. Additionally, prevention clinical trials are starting to evaluate multi-agent cancer prevention approaches, with the hope of improved efficacy over single agents. Finally, there is a push to increase the use of chemopreventive agents with proven efficacy, such as tamoxifen and raloxifene, in the prevention of breast cancer.