Comparison of Survival Outcomes for Axillary Surgery Extent Based on Intraoperative Sentinel Lymph Node Biopsy Result After Neoadjuvant Chemotherapy for Breast Cancer

PURPOSE To investigate the survival difference between limited axillary surgery and full axillary lymph node dissection (ALND) in patients with 1-3 positive sentinel lymph node biopsies (SLNBs) after neoadjuvant chemotherapy (NAC). METHOD We retrospectively analyzed data from 676 patients who underwent surgery between 2007 and 2017 with cT1-4, cN0-3, cM0 breast cancer at the time of diagnosis and 1-3 positive SLNBs after NAC. The patients received either SLNB only or completed level I or II ALND based on SLNB results. After propensity score matching, 483 patients who had undergone SLNB only (n = 188) and ALND (n = 295) were included. We examined overall survival, axillary recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival and compared them between the subgroups. RESULT At a median follow-up of 59.4 months, no significant statistical difference was observed in overall survival, axillary recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival between SLNB only and ALND. No significant differences were observed in the 5-year axillary recurrence-free survival (93.1% vs. 94.0%, hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.43-2.05, p = 0.876) and 5-year overall survival (97.7% vs. 97.3%, HR = 1.65, 95% CI = 0.58-4.65, p = 0.347) between the two groups. CONCLUSION Our analysis suggests that SLNB alone may be a possible option for patients with 1-3 sentinel node-positive breast cancer following NAC without significant compromise of recurrence or overall survival.