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.