Axillary dissection versus no axillary dissection in women with invasive breast cancer and sentinel node metastasis

Question: Does a complete axillary lymph node dissection (ALND) affect the overall survival of patients with sentinel lymph node (SLN) metastasis of breast cancer? Design: Randomized controlled trial. Setting: Multicentre trial that included 115 sites. Patients: There were 856 women with clinical T1–T2 invasive breast cancer, with no palpable adenopathy and 1–2 SLNs containing metastases identified histologically. Intervention: All patients underwent lumpectomy and tangential whole-breast irradiation. Those with SLN metastases indentified by sentinel lymph node dissection (SLND) were randomly assigned to undergo ALND or no further axillary treatment. Those assigned to ALND underwent dissection of at least 10 nodes. Main outcome measures: Overall survival, defined as the time from random assignment until death from any cause. The secondary outcome was disease-free survival. Results: Clinical and tumour characteristics were similar among 420 patients assigned to ALND and 436 assigned to SLND alone. The median number of nodes removed was 17 with ALND and 2 with SLND. At a median follow-up of 6.3 years (last follow-up, Mar. 4, 2010), 5-year overall survival was 91.8% (95% confidence interval [CI] 89.1%–94.5%) with ALND and 92.5% (95% CI 90.0%–95.1%) with SLND alone; 5-year disease-free survival was 82.2% (95% CI 78.3%–86.3%) with ALND and 83.9% (95% CI 80.2%–87.9%) with SLND alone. The hazard ratio for treatment-related overall survival was 0.79 (90% CI 0.56–1.11) without adjustment and 0.87 (90% CI 0.62–1.23) after adjusting for age and adjuvant therapy. Conclusion: Among patients with limited SLN metastatic breast cancer treated with breast conservation and systemic therapy, the use of SLNB alone compared with ALND did not result in inferior survival.