Comparable survival between pN0 breast cancer patients undergoing sentinel node biopsy and extensive axillary dissection: a report from the Korean Breast Cancer Society.

PURPOSE: Recent studies showing survival benefit of extensive axillary lymph node dissection (ALND) in pN0 breast cancer have challenged the concept of sentinel node biopsy (SNB). In this study, the survival and recurrence after SNB alone and ALND in pN0 Korean breast cancer patients were investigated. PATIENTS AND METHODS: Using information from two large databases, including a Korean nationwide registry, we assessed survival relative to the extent of ALND in pN0 breast cancer patients. We also compared the survival of pN0 patients who underwent SNB alone with survival in those who underwent varying degrees of ALND.
RESULTS: In an analysis of 1,607 pN0 patients from a single institution, less extensive ALND significantly increased the risks of breast cancer death and systemic recurrence but not of locoregional recurrence. These findings were validated by an analysis of nationwide registry data on 17,672 pN0 patients; patients with > 20 dissected lymph nodes had significantly better overall survival (OS) and breast cancer-specific survival (BCSS) than those with 10 to 20 or < 10 dissected lymph nodes. Patients who underwent SNB alone showed OS (hazard ratio [HR], 1.03; 9% CI, 0.08 to 1.56) and BCSS (HR, 1.15; 95% CI, 0.75 to 1.78) similar to those of patients who underwent extensive ALND (> 20 dissected lymph nodes), despite the small number of lymph nodes removed.
CONCLUSION: Extensive ALND is associated with better survival and less systemic recurrence than less extensive ALND in patients with pN0 breast cancer. However, SNB alone showed excellent survival results, similar to those of extensive ALND, supporting the long-term oncologic safety of SNB.