Patterns of management of positive sentinel lymph nodes in breast cancer patients after the American College of Surgeons Oncology Group Z0011 trial: A retrospective cohort.

Abstract

e12584 Background: The ACOSOG-Z0011 clinical trial introduced significant changes to the traditional surgical management of early breast cancer with positive sentinel lymph nodes (SLNs). This study evaluates the impact of these changes on the surgical practices for early breast cancer at our institution. Methods: This retrospective chart review included Lebanese women diagnosed with invasive breast cancer who underwent upfront breast-conserving surgery and sentinel lymph node biopsy (SLNB) without prior chemotherapy, all having no distant metastasis and one or more positive SLNs. Results: Our cohort consisted of 242 females with a median age of 52.8 years (range: 28.6-83.6). The most prevalent subtypes were Luminal A (n = 131) and Luminal B (n = 82), followed by triple-negative (n = 21) and HER-2 positive (n = 8). Grade 2 breast cancer was the most common (n = 110), followed by grades 1 and 3 (n = 64 and n = 67, respectively). Among the 230 patients with clinically negative nodes, 180 (78%) had negative nodes on surgical sentinel pathology. Of the positive SLNs, micro and macro metastases were observed in 5.5% and 94% of cases, respectively. Notably, 40.9% of cases had 2 or fewer SLNs retrieved, while 23.2% had more than 5 (median: 3, range: 1-12). Analysis of axillary lymph node dissection (ALND) rates showed that between 2011 and 2013, 46.7% of patients with 1 or 2 positive lymph nodes underwent ALND, whereas between 2014 and 2016, this rate decreased to 18.2%. Follow-up data indicated low rates of locoregional recurrence (LRR), with 5- and 10-year rates of 1.72% and 2.15%, respectively. Disease-free survival (DFS) stood at 95.3% at both 5 and 10 years, with nodal recurrence at 5 years at 0.4%. The overall survival rate at 10 years was 98.7%. Conclusions: Our study demonstrates that SLNB alone is not inferior to ALND regarding oncologic outcomes, particularly overall survival and disease-free survival. These findings align with those of the Z0011 trial and further support its generalizability to diverse ethnic populations, including those at our institution.