D134. Comparison of Nipple-sparing Mastectomy versus Skin-sparing Mastectomy in Bilateral Implant-based Breast Reconstruction with Unilateral Radiotherapy: A Matched Cohort Study

Abstract

PURPOSE: Nipple-sparing mastectomy (NSM) preserves natural nipple-areola complex and entire native breast skin with a goal of better cosmetic outcomes in breast reconstruction. In bilateral tissue expander (TE)/implant-based reconstruction requiring unilateral post-mastectomy radiotherapy (PMRT), progressive radiation-induced fibrosis can lead to increasing nipple asymmetry with cosmetic dissatisfaction. Thus, PMRT may ultimately negate the intended positive cosmetic value of NSM compared to skin-sparing mastectomy (SSM). This study compares, 1) surgical complications, 2) patient satisfaction, and 3) aesthetic outcomes between NSM vs. SSM in bilateral implant-based reconstruction with unilateral PMRT. METHOD: This retrospective matched cohort study included consecutive NSM patients with TE/implant breast reconstruction + unilateral PMRT matched 1:2 to SSM group. All patients completed PMRT and TE exchange to implants. Demographics, oncologic stage, co-morbidities, and complication data were collected. Patient satisfaction was evaluated by BREAST-Q. Aesthetic outcome was assessed by blinded reviewers with a 5-point Likert scale. RESULTS: Among 58 patients who underwent bilateral TE/implant reconstruction with unilateral PMRT, 17 NSM patients were matched to 41 SSM patients by age, BMI, and co-morbidities. No significant difference existed between overall surgical complications (p=0.2) and BREAST-Q questionnaire scores. The average adverse effects of radiation score was higher in the NSM. Preliminary aesthetic outcomes demonstrated higher total average aesthetic score in SSM compared to NSM. CONCLUSION: Although NSM is generally associated with better cosmetic outcome compared to SSM, it has far less impact in bilateral implant-based breast reconstruction with unilateral PMRT. This may be related to the additional negative post-radiotherapy impact on nipple asymmetry.