Improved overall survival after contralateral risk‐reducing mastectomy in BRCA1/2 mutation carriers with a history of unilateral breast cancer: A prospective analysis

Abstract

Data on survival of BRCA1/2-associated primary breast cancer (PBC) patients who opt for subsequent contralateral riskreducing mastectomy (CRRM) are scarce and inconsistent. We examined the efficacy of CRRM on overall survival in mutation carriers with a history of PBC. From a Dutch multicentre cohort, we selected 583 BRCA-associated PBC patients, being diagnosed between 1980 and 2011. Over time, 242 patients (42%) underwent CRRM and 341 patients (58%) remained under surveillance. Survival analyses were performed using Cox models, with CRRM as a time-dependent covariate. The median follow-up after PBC diagnosis was 11.4 years. In the CRRM group, four patients developed contralateral breast cancer (2%), against 64 patients (19%) in the surveillance group (p < 0.001). The mortality was lower in the CRRM group than in the surveillance group (9.6 and 21.6 per 1000 person-years of observation, respectively; adjusted hazard ratio 0.49, 95% confidence interval 0.29-0.82). Survival benefit was especially seen in young PBC patients (<40 years), in patients having a PBC with differentiation grade 1/2 and/or no triple-negative phenotype, and in patients not treated with adjuvant chemotherapy.

Triple-Negative versus Non–Triple-Negative Breast Cancers in High-Risk Women: Phenotype Features and Survival from the HIBCRIT-1 MRI-Including Screening Study

“…In fact, the rate of patients treated with adjuvant chemotherapy in our study was over 2-fold higher for TNBC than for non-TNBC patients (100% vs. 44%), while less than 50% of TNBC patients received adjuvant chemotherapy in the Toronto cohort. The role of more effective treatment protocols in improving the outcome of TNBC patients is also supported by a recent report showing a substantially improved overall survival after contralateral riskreducing mastectomy in BRCA mutation carriers with a history of unilateral breast cancer (41). Moreover, the lower rate of contralateral prophylactic mastectomies in our non-TNBCs was associated with a higher occurrence of contralateral breast cancer relapses.…”

Breast cancer in young women

“…The risk for cancer in the other breast among BRCA carriers has been estimated at 3-4% annually. Therefore, preventive mastectomy of the other breast should be offered to these patients as such management greatly improves the OS [30]. Nipple-areola complex sparing mastectomy allows to maintain oncologic safety and achieve good effects after the subsequent reconstructive surgery.…”

Is Mastectomy Oncologically Safer than Breast-Conserving Treatment in Early Breast Cancer

“…For patients who are already diagnosed with or have been treated for unilateral breast cancer and who were tested positive for a BRCA1 or BRCA2 mutation, a potential benefit of a bilateral mastectomy (if BCT is possible for the affected breast) or a CPM has not been clearly demonstrated so far: As we know, the rate of a second occurrence of ipsilateral metachronic breast cancer is not higher in comparison to non-mutation carriers [45]. Although the incidence of contralateral breast cancer can be reduced by a CPM, there are still insufficient followup data to postulate a positive impact on OS [46]. In this context, particularly the patient's age at first diagnosis has to be taken into consideration in order to maintain adequate counseling on the remaining life-time risk [47].…”