Equivalent survival after nipple-sparing compared to non-nipple-sparing mastectomy: data from California, 1988-2013

Nipple-sparing mastectomy, which may improve cosmesis, body image, and sexual function in comparison to non-nipple-sparing mastectomy, is increasingly used to treat early-stage breast cancer; however, long-term survival data are lacking. We evaluated survival after nipple-sparing mastectomy versus non-nipple-sparing mastectomy in a population-based cancer registry.

We conducted an observational study using the California Cancer Registry, considering all stage 0-III breast cancers diagnosed in California from 1988 to 2013. We compared breast cancer-specific and overall survival time after nipple-sparing versus non-nipple-sparing mastectomy, using multivariable analysis.

Among 157,592 stage 0-III female breast cancer patients treated with unilateral mastectomy from 1988-2013, 993 (0.6 %) were reported as having nipple-sparing and 156,599 (99.4 %) non-nipple-sparing mastectomies; median follow-up was 7.9 years. The proportion of mastectomies that were nipple-sparing increased over time (1988, 0.2 %; 2013, 5.1 %) and with neighborhood socioeconomic status, and decreased with age and stage. On multivariable analysis, nipple-sparing mastectomy was associated with a lower risk of breast cancer-specific mortality compared to non-nipple-sparing mastectomy [hazard ratio (HR) 0.71, 95 % confidence interval (CI) 0.51-0.98]. However, when restricting to diagnoses 1996 or later and adjusting for a larger set of covariates, risk was attenuated (HR 0.86, 95 % CI 0.52-1.42).

Among California breast cancer patients diagnosed from 1988-2013, nipple-sparing mastectomy was not associated with worse survival than non-nipple-sparing mastectomy. These results may inform the decisions of patients and doctors deliberating between these surgical approaches for breast cancer treatment.