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

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.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.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 0.001) over 5 years. Compared to patients receiving UM only, patients receiving CPMs had significantly higher reconstruction rates (p 0.001), which did not significantly change over time (p = 0.551) and tended to be younger (p 0.001).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.