Comparison of Patient Characteristics and Outcomes of Contralateral Prophylactic Mastectomy and Unilateral Total Mastectomy in Breast Cancer Patients

There has been an increasing trend toward contralateral prophylactic mastectomy (CPM) in the management of breast cancer (BCa). This study's objective was to compare clinicopathologic characteristics of BCa patients who elected CPM to those who elected unilateral total mastectomy (UTM) and to determine whether CPM improved survival. Comparison was performed on 355 patients with stage 0-III BCa matched by age and stage who underwent mastectomy from 1995 to 2008: 177 patients had CPM; 178 patients had UTM. Clinicopathological characteristics and survival outcomes were analyzed. Women who underwent preoperative MRI were twice as likely to have CPM (40.9 vs. 19.7%, P < 0.001). MRI identified additional suspicious foci in 45% CPM and 19% UTM. Patients with history of previous breast biopsies, family history, or BRCA mutation were more likely to choose CPM than UTM (40.1 vs. 24%, P = 0.001; 64.3 vs. 41.4%, P < 0.001; 20.3 vs. 6.5%, P = 0.04, respectively). CPM patients elected nipple preservation (26 vs. 5.2%, P < 0.001) and immediate reconstruction more often (92.2 vs. 73.5%, P < 0.001); UTM patients were more likely to have attempted breast conservation prior to mastectomy (52.8 vs. 39.5%, P = 0.01). CPM identified occult BCa in 11 patients (6.6%), and three UTM patients (1.7%) developed contralateral BCa. With median follow-up of 61 months, by univariable/multivariable analyses, CPM did not improve overall, disease-free, or distant metastases-free survival. Factors that may influence choice of CPM included preoperative MRI, history of prior breast biopsies, immediate reconstruction, nipple preservation, family history, and BRCA status. Those who chose CPM did not have improved survival.