Based on studies that show benefits of estrogen and androgen blockers in reducing breast cancer risk in high-risk women, the United States Preventative Service Task Force (USPSTF) recommends that clinicians offer risk-reducing medications to women at increased risk for breast cancer; however, they recommend against routine use of these medications in average-risk women.
Hormone receptor blockers (such as tamoxifen and raloxifene) and aromatase inhibitors (such as exemestane and anastrozole), reduce the risk of invasive breast cancer, but also potentially cause adverse side-effects including cataracts and bleeding disorders. Women at increased risk for breast cancer should have a conversation with their doctors to discuss the benefits and adverse effects of breast cancer risk-reducing medications.
Check out the full article at: https://tinyurl.com/ww4rf5r
and USPSTF recommendations at: https://www.ncbi.nlm.nih.gov/pubmed/31509365