Decreasing contralateral prophylactic mastectomy rates in average-risk women with unilateral breast cancer.

Abstract Background Contralateral prophylactic mastectomy (CPM) is not recommended for average-risk women with breast cancer due to lack of evidence for survival benefit, yet recent studies demonstrate increasing CPM rates. Methods We identified patients with breast cancer treated with unilateral mastectomy (UM) with or without CPM. Rates of malignancy in CPM specimens and factors in CPM rates were assessed. Results From 2013 to 2017, 1353 patients had UM and 355 had CPM. Our institution’s occult malignancy detection rate was 5.04%. CPM rates decreased from 31.6% to 17.3% (p  Conclusions Patients having UM have low risk of contralateral malignancy. CPM is associated with younger age and breast reconstruction, suggesting factors to identify for patient and provider education.