 Testing in an average-risk person is particularly likely to return one of these indeterminate, useless results.Removing the second breast in a person who has breast cancer (contralateral risk‐reducing mastectomy or CRRM) may reduce the risk of cancer in the second breast, however, it is unclear if removing the second breast in those who have breast cancer improves survival.The selective estrogen receptor modulators (such as tamoxifen) reduce the risk of breast cancer but increase the risk of thromboembolism and endometrial cancer.