Long-Term Follow-Up of Surgical Outcomes and Oncological Results of Nipple-Sparing Mastectomy with Immediate Reconstruction Through a Single Axillary Incision with Different Approach Methods

Background: We investigated the perioperative outcome and oncologic safety of performing nipple-sparing mastectomy (NSM) through a single axillary incision (NSM-SAI) compared with performing NSM through a conventional incision (NSM-C). Methods: We retrospectively reviewed 725 patients who underwent NSM for breast cancer between January 2010 and December 2023; 333 patients who underwent NSM with immediate reconstruction (IR) were enrolled. Surgical outcomes and oncologic outcomes of NSM-C (n = 184), NSM performed through SAI with a freehand approach (NSM-SAI-F; n = 92), and with an endoscopic approach (NSM-SAI-E; n = 57) were demonstrated. The risk factors for resection margins, nipple-areolar complex (NAC), and skin flap necrosis were evaluated separately for NSM-C and NSM-SAI. Results: NAC and skin flap necrosis occurrence rates among the NSM-C, NSM-SAI-F, and NSM-SAI-E groups were similar (insignificant), regardless of autologous or prosthesis reconstruction. The tumor-to-nipple distance among patients who underwent NSM-C was an independent risk factor for NAC necrosis in the NSM-C group (odds ratio [OR] 6.02, p = 0.007); being overweight and tumor location in the lower breast were risk factors for skin necrosis in the NSM-C group (OR 3.36, p = 0.041; and OR 4.32, p = 0.011, respectively). These risk factors were not associated with the NSM-SAI group. The three groups had comparable positive resection margins, local recurrence-free survival, and distant metastasis-free survival rates (p = 0.857, 0.543, and 0.975, respectively). Conclusions: NSM-SAI combined with IR by the freehand or endoscopic approaches can provide good aesthetic outcomes and oncologic safety for well-selected patients with breast cancer. The risk factors for NAC and skin flap necrosis differ between the NSM-SAI and NSM-C groups.