Patterns of Management of Positive Sentinel Lymph Nodes in Breast Cancer Patients After the American College of Surgeons Oncology Group Z0011 Trial: A Retrospective Study.

BACKGROUND

Breast cancer is the most prevalent malignancy among women and the leading cause of cancer-related mortality. Sentinel lymph node biopsy (SLNB) has emerged as an alternative to axillary lymph node dissection (ALND), with the ACOSOG Z0011 trial demonstrating that SLNB alone yields equivalent oncologic outcomes to ALND for patients with 1-2 positive sentinel lymph nodes (SLNs).

OBJECTIVE

This study evaluates the adoption of Z0011 recommendations at the American University of Beirut Medical Center (AUBMC) and their impact on oncologic outcomes.

METHODS

This retrospective cohort study includes female patients with early-stage breast cancer (T1-T2, N0, M0) who underwent breast-conserving surgery with SLNB at AUBMC, between January 2011 and December 2016. Data were extracted from the institutional breast cancer database, including demographics, tumor characteristics, surgical management, and follow-up outcomes.

RESULTS

SLNB alone was adopted, following publication of the Z0011 trial, in 93.4% of patients, with 6.6% undergoing ALND. Among patients with 1-2 positive SLNs, 27.1% underwent completion ALND. The median number of lymph nodes retrieved increased from two to four over the study period. The most common molecular subtypes observed were luminal A (54.1%), characterized by a predominant stage T1 presentation and small tumor sizes (median tumor size, 1.4 cm). Among patients with 1-2 positive SLNs who underwent ALND, no recurrences or metastatic events were reported. The 5-year overall survival (OS) and disease-free survival (DFS) rates were 95.9% and 93.4%, respectively. No notable differences in OS and DFS were observed between the SLNB alone and ALND groups.

CONCLUSIONS

Our study demonstrates that SLNB alone provides comparable oncologic outcomes to ALND, supporting its safety and effectiveness as an alternative for early-stage breast cancer patients with 1-2 positive SLNs. These findings extend the Z0011 trial's applicability to diverse populations, reinforcing SLNB as a less invasive, safe alternative to ALND.