Level 1: Likely reliable evidence

Sentinel lymph node (SLN) resection has been advocated as an option to reduce morbidity for women undergoing surgery for breast cancer. When the sentinel node is negative for breast cancer, SLN resection without axillary lymph node dissection (ALND) should minimize such adverse effects as arm swelling, numbness, and tingling. New reports from the National Surgical Adjuvant Breast and Bowel Project B-32 trial show that SLN resection is as effective for survival as ALND and may reduce postsurgical morbidity and symptoms in node-negative women. A total of 5,611 women with invasive breast cancer and clinically negative nodes were randomized to SLN resection with ALND only if SLN-positive vs. immediate ALND without waiting for biopsy results. The primary analysis was performed on 3,986 women (71%) who were SLN-negative. There were no significant differences between groups in overall survival (90.3% vs. 91.8%) or progression-free survival (81.5% vs. 82.4%) over eight years. There were also no significant differences in local recurrence (2.4% vs. 2.7%), distant metastases (3.2% vs. 2.8%), cancer in the opposite breast (2.2% vs. 2.8%), or second non-breast cancer (5.4% vs. 4.5%) (Lancet Oncol. 2010;11:927-933).

In a report of three-year postsurgical follow-up, SLN resection alone was associated with reductions in residual arm tingling (7.5% vs. 13.5%, P <0.001, NNT 17) and numbness (8.1% vs. 31.1%, P <0.001, NNT 5). It was also associated with lower rates of significant shoulder abduction deficits (5.7% vs. 9%, P <0.001, NNT 31), and arm volume differences (7.5% vs. 14.3%, P <0.001, NNT 15) (Level 2: Mid-level evidence) (J Surg Oncol. 2010;102:111-118). In a subgroup of 749 women with negative SLNs who completed symptom questionnaires, SLN resection alone was associated with reduced rates of bothersome arm symptoms, restricted work and social activity, and impaired quality of life (J Clin Oncol. 2010;28:3929-3936).