Effect of axillary lymph node dissection after sentinel lymph node biopsy on overall survival in patients with T1 or T2 node-positive breast cancer: report from the Korean Breast Cancer Society.

BACKGROUND: The effect of axillary lymph node dissection (ALND) after sentinel lymph node biopsy (SLNB) in patients with clinically node-negative patients in preoperative evaluations on overall survival (OS) is uncertain. The study aimed to evaluate the difference of survival between node-positive patients who underwent SLNB alone and those who received ALND after SLNB using the Korean Breast Cancer Society registry. METHODS: We enrolled 2,581 patients who met the eligibility criteria. All enrolled patients had T1 or T2 breast cancer, and received mastectomy or breast-conserving treatment followed by documented adjuvant systemic therapy. RESULTS: There were 197 patients with SLNB alone and 2,384 patients with ALND after SLNB. Smaller tumor size, lower number of nodal metastasis, and higher proportion of breast-conserving surgery were found in patients with SLNB alone than in those with ALND after SLNB. There was no significant difference in OS between the two groups by the log-rank test. ALND after SLNB showed no significant improvement in OS in multivariate analysis. CONCLUSIONS: ALND in patients with sentinel metastasis who have T1 or T2 breast cancer receiving adjuvant systemic therapy may not have improved OS.