Background: Nipple-sparing mastectomy (NSM) is an increasingly common procedure; however, concerns exist regarding its oncological safety due to the potential for residual breast tissue to harbor occult malignancy or future cancer.
Methods: A systematic literature review was performed. Studies with internal comparison arms evaluating therapeutic NSM versus skin-sparing mastectomy (SSM) and/or modified radical mastectomy (MRM) were included in a meta-analysis of overall survival (OS), disease-free survival (DFS), and local recurrence (LR). Studies lacking comparison arms were only included in the systematic review to evaluate mean OS, DFS, LR, and nipple-areolar recurrence (NAR).
Results: The search yielded 851 articles. Twenty studies with 5594 patients met selection criteria. The meta-analysis included eight studies with comparison arms. Seven studies that compared OS found a 3.4% risk difference between NSM and MRM/SSM, five studies that compared DFS found a 9.6% risk difference between NSM and MRM/SSM, and eight studies that compared LR found a 0.4% risk difference between NSM and MRM/SSM. Risk differences for all outcomes were not statistically significant. The systematic review included all 20 studies and evaluated OS, DFS, LR, and NAR. Studies with follow-up intervals of <3 years, 3-5 years, and >5 years had mean OS of 97.2, 97.9, and 86.8%; DFS of 93.1, 92.3, and 76.1%; LR of 5.4, 1.4, and 11.4%; and NAR of 2.1, 1.0, and 3.4%, respectively.
Conclusions: This study did not detect adverse oncologic outcomes of NSM in carefully selected women with early-stage breast cancer. Use of prospective data registries, notably the Nipple-Sparing Mastectomy Registry, will add clarity to this important clinical question.