Residual Cancer Burden in Two-Stage Nipple Sparing Mastectomy after First Stage Lumpectomy and Devascularization of the Nipple Areolar Complex

Abstract

Purpose Ischemic complications after nipple-sparing mastectomy (NSM) can be ameliorated by 2-stage procedures wherein devascularization (1S) of the nipple-areolar complex (NAC), lumpectomy, and nodal staging surgery is performed first prior to nipple sparing mastectomy (2S). We report amount of residual disease at NSM and time interval between procedures to evaluate the oncologic safety of this approach. Methods Women with breast cancer who received 2S NSM from 2015–2022 were identified. Both patient level and breast level analyses were conducted. Baseline disease amount was defined by preoperative imaging and confirmed by 1S pathology, and residual disease was defined by 2S pathology. The number of breasts with residual disease were calculated and subdivided into microscopic (1-2mm), minimal (3-10mm), and moderate (> 10mm) residual disease. Results 59 patients (108 breasts) underwent 2S NSM. Of the 60 breasts with invasive carcinoma on 1S pathology, 65% (39/60) had no residual invasive disease on 2S pathology and 40% (24/60) had no residual invasive or in situ disease on final 2S. Most (56%) cases with residual invasive cancer had less than 10 mm of invasive disease on 2S pathology. The overall median time interval between 1S and 2S for all patients was 34 days—31 days for invasive and 41 days for DCIS subsets. Completion NSM was performed within 6 weeks for 72% (42 patients/82 breasts) of the breasts analyzed. Conclusion Invasive cancers were completely resected during 1S procedure in 65% of breasts. Residual disease was minimal and there was not significant upstaging of disease at 2S.