Can axillary radiotherapy replace axillary dissection for patients with positive sentinel nodes? A systematic review and meta-analysis

OBJECTIVE To compare the efficacy of axillary radiotherapy (ART) with that of completion axillary lymph node dissection (cALND) in clinically node-negative breast cancer patients with a positive sentinel lymph node. METHODS A literature search was performed in PubMed, EMBASE and Cochrane Library by using the search terms "breast cancer", "sentinel lymph node biopsy", "axillary radiotherapy" or "regional node irradiation" for articles published between 2004 and 2016. Only randomized controlled trials that included patients with positive sentinel nodes were included in the meta-analysis. RESULTS Two randomized controlled trials and three retrospective studies were identified. The reported overall survival rate (hazard ratio [HR] = 1.09, 95% confidence interval [CI]: 0.75-1.43, P = 0.365), disease-free survival rate (HR = 1.01, 95% CI: 0.58-1.45, P = 0.144), and axillary recurrence rate (1.2% and 0.4%, and 1.3% and 0.8%, respectively) were similar in both groups. The absence of knowledge on the extent of nodal involvement in the ART group appeared to have no major impact on the administration of adjuvant systemic therapy. CONCLUSIONS ART is not inferior to cALND in the patients with clinically node-negative breast cancer who had a positive sentinel lymph node. Information obtained by using cALND after SLNB may have no major impact on the administration of adjuvant systemic therapy.