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

Purpose The ACOSOG-Z0011 clinical trial introduced drastic changes to the traditional surgical practice for early breast cancer with positive sentinel lymph nodes. This study evaluates how these changes have affected the surgical management of early breast cancer at our institution. Methods A retrospective chart review was conducted for Lebanese women with a diagnosis of invasive breast cancer and who were ≥18 years of age, had undergone upfront breast-conserving surgery, and SLNB without any prior chemotherapy had no distant metastasis and had one or more positive SLNs, between 2011 and 2016. Results Data from our cohort shows that 78% of patients out of the 233 with clinically negative nodes go on to have negative nodes on surgical sentinel pathology as well. However, the incidence of micromets is 5.5% amongst positive SLNs versus 94% of positive SLNs having macromets. Survival data analysis showed a 5-year and 10-year locoregional recurrence rates of 1.72% and 2.15%, respectively. At 3-years follow-up, distant metastasis occurred in 3.4% of cases. Additionally, the 10-year overall survival is 98.7% and disease-free survival is 95.3%. The rates of ALND decreased from 46.7% to 18.2% in patients with 2 or less positive sentinel nodes between the two time periods 2011-2013 and 2014-2016. Conclusion With a follow-up period extending more than five years, our study shows that ALND offers no superiority to SLNB alone in terms of overall survival and disease-free survival. This does not only conform with the findings of Z0011 but adds to its generalizability to populations of different ethnicities.