Importance Nipple-sparing mastectomy (NSM) offers superior cosmetic outcomes and has been gaining wide acceptance; however, its role among patients with BRCA mutations remains controversial.

Objective To report on the oncologic safety of NSM and provide evidence-based data to patients and health care professionals regarding preservation of the nipple-areolar complex during a risk-reducing mastectomy in a population with BRCA mutations.

Design, Setting, and Participants We retrospectively reviewed the outcomes of 9 institutions’ experience with prophylactic NSM from 1968 to 2013 in a cohort of patients with BRCA mutations. Patients with breast cancer were included if they underwent contralateral risk-reducing mastectomy; however, only the prophylactic side was considered in the analysis. Patients found to have an occult primary breast cancer at the time of risk-reducing mastectomy, those having variant(s) of unknown significance, and those undergoing free nipple grafts were excluded.

Main Outcomes and Measures The primary outcome measure was development of a new breast cancer after risk-reducing NSM. Three reference data sources were used to model the expected number of events, and this was compared with our observed number of events.

Results A total of 548 risk-reducing NSMs in 346 patients were performed at 9 institutions. The median age at NSM was 41 years (interquartile range, 34.5-47.5 years). Bilateral prophylactic NSMs were performed in 202 patients (58.4%), and 144 patients (41.6%) underwent a unilateral risk-reducing NSM secondary to cancer in the contralateral breast. Overall, 201 patients with BRCA1 mutations and 145 with BRCA2 mutations were included. With median and mean follow-up of 34 and 56 months, respectively, no ipsilateral breast cancers occurred after prophylactic NSM. Breast cancer did not develop in any patients undergoing bilateral risk-reducing NSMs. Using risk models for BRCA1/2 mutation carriers, approximately 22 new primary breast cancers were expected without prophylactic NSM. Prophylactic NSM resulted in a significant reduction in breast cancer events (test of observed vs expected events, P < .001).

Conclusions and Relevance Nipple-sparing mastectomies are highly preventive against breast cancer in a BRCA population. Although the follow-up remains relatively short, NSM should be offered as a breast cancer risk–reducing strategy to appropriate patients with BRCA mutations.

重要性 保留乳头的乳房切除术（NSM）可提供出色的美容效果，并已获得广泛认可。然而，其在BRCA突变患者中的作用仍存在争议。

目的 报告NSM的肿瘤学安全性，并为患者和医疗保健专业人员在BRCA突变人群中降低风险的乳腺切除术中乳头-乳晕复合物的保存提供循证数据。

设计，设置和参与者 我们回顾性回顾了1968年至2013年间9所机构在一组BRCA突变患者中预防性NSM经验的成果。如果乳腺癌患者接受了降低对侧风险的乳房切除术，则将其包括在内；但是，在分析中仅考虑了预防方面。在降低风险的乳腺切除术中发现患有隐匿性原发性乳腺癌的患者，具有未知意义的变体和进行游离乳头移植的患者被排除在外。

主要结果和措施 主要结果指标是降低风险的NSM后发生新的乳腺癌。使用三个参考数据源对事件的预期数量进行建模，并将其与我们观察到的事件数量进行比较。

结果 在9家机构中，共346例患者中执行了548种降低风险的NSM。NSM的中位年龄为41岁（四分位间距为34.5-47.5岁）。202例患者（58.4％）进行了双侧预防性NSM，144例患者（41.6％）进行了对侧乳癌继发于癌症的单侧降低风险的NSM。总体上，包括201例BRCA1突变的患者和145例BRCA2突变的患者。中位和平均随访分别为34和56个月，预防性NSM后未发生同侧乳腺癌。接受双侧降低风险的NSM的任何患者均未发生乳腺癌。对BRCA1 / 2使用风险模型突变携带者中，预计约有22种新的原发性乳腺癌没有预防性NSM。预防性NSM导致乳腺癌事件显着减少（观察到的预期事件检验，P  <.001）。

结论和相关性 保留乳头的乳房切除术在BRCA人群中对乳腺癌具有高度的预防作用。尽管随访时间相对较短，但应为适当的BRCA突变患者提供NSM作为降低乳腺癌风险的策略。