Intraoperative Examination of Retro-Areolar Margin is not Routinely Necessary During Nipple-Sparing Mastectomy for Cancer

Background: Intraoperative examination of retro-areolar margin (IERM) often is used during nipple-sparing mastectomy (NSM) for cancer, but there is no robust data regarding its real advantage. Methods: Consecutive patients undergoing NSM for cancer with omission of IERM according to institutional protocols from 2016 to 2021 were retrospectively analyzed. The decision to maintain or remove the Nipple-Areola Complex (NAC) after definitive pathology was taken at the multidisciplinary meeting. Results: Among 162 women operated in the study period, the presence of neoplastic cells within 2 mm from the inked retroareolar margin (RAM) was detected at permanent pathology in 17 cases (10.5%). Nipple-Areola-Complex (NAC) was removed postoperatively in five patients (3%) for margins <1 mm, the other 12 were observed, whereas postoperative NAC necrosis required surgical removal in additional five cases (3%). The NAC was thus preserved in 152 of 162 patients (94%). At multivariate analysis, RAM ≤2 mm was associated with radiological tumor-to-nipple distance less than or equal to 1 cm (p = 0.04) and Ki67 label index ≥ 20 (p = 0.04), whereas multifocality/multicentricity showed a trend towards significance (p = 0.07). At a median follow-up of 46 months, five locoregional relapses occurred (3%), only one of them involving the NAC (0, 6%). Locoregional relapse and overall survival for patients with RAM > or < 2 mm were not different. Conclusions: IERM is not routinely necessary during NSM for cancer, because its omission is associated with a very low return to the operating room, it is oncologically safe, and associated pitfalls are avoided. Further studies are necessary to confirm these findings.