Neoadjuvant chemotherapy as an indication to preserve nipple areolar complex in advanced breast cancer.

e12655 Background: Nipple areolar skin sparing mastectomy (NASSM) has similar oncologic and surgical safety compared to skin sparing mastectomy (SSM) and conventional mastectomy. It provides a superior cosmetic outcome, patient satisfaction and quality of life. With the increasing rate of pathological response rate with neoadjuvant chemotherapy (NAT), nipple preservation can be achieved. The aim of our study is to evaluate whether NASSM is an appropriate surgical procedure for patients in whom there is radiological evidence of extension or involvement of nipple areolar complex (NAC) prior to NAT. Methods: Patients with advanced breast cancer received neoadjuvant chemotherapy and NASSM or SSM between June 2006 and December 2021 at Asan Medical Center were retrospectively reviewed. We excluded patients with metastatic breast cancer on presentation, bilateral cancer and inflammatory breast cancer. Kaplan-Meier survival analysis and Cox proportional hazard models were applied to determine clinicopathological and radiological factors to determine NAC preservation. Our primary objective to assess tumor cells persistence in the NAC after radiological complete response or resolution of extension to NAC. Results: Total of 1,105 patients included. 71.7% of patients underwent NASSM and 17.2% SSM as a final operation. 144 patients (13%) had a change in the pre- NAT type of surgery decision. 83(7.5%) patients had nipple involvement on final pathology. Out of 312 patients who underwent SSM, only 76 patients had nipple involvement on final pathology When comparing patients who had nipple involvement to those who didn’t on final pathology, clinical T & N stage, histologic & nuclear grade, breast cancer subtype, presence of multifocality/multicentric disease on MRI pre or post NAT, distance of mass to NAC and mass size pre and post NAT, the presence of non mass extension to NAC post NAT, NAC thickening on any image pre and post NAT and presentation symptoms of nipple retraction and skin changes were statistically significant. A multivariate regression analysis was performed to compare all the above factors and showed that breast cancer subtype, tumor nipple distance on MRI pre NAT, nipple areolar thickening on MRI pre NAT, clinical response and nipple retraction on MMG post NAT were statistically significant and indicators of nipple involvement on final pathology. Only 8 patients developed NAC recurrence in the NASSM group. Conclusions: NASSM is a safe procedure in patients who had tumor extension to NAC prior to NAT and showed improvement post NAT as evident on MRI. Further prospective studies are needed to establish and criteria to preserve NAC in this subgroup of patients.