Efficacy and safety of omitting axillary lymph node dissection in early breast cancer patients with sentinel-node metastases: a systematic review and meta-analysis

Objective: This systemic meta-analysis aimed to evaluate the efficacy and safety of omitting axillary lymph node dissection in early stage of breast cancer (T1-2) with positive sentinel lymph node (SLN) and without palpable lymphadenopathy. Methods: All available literature of randomized controlled trials (RCT) and cohort studies was pooled from Cochrane library, PubMed, Medline, OVID, Springer Linker, Science Direct, EBSCO. Relevant references were also manually retrieved. The primary outcome was efficacy, including overall survival, disease-free survival, local recurrence. The secondary outcome was safety, including the lymphedema, neuropathy, and dysfunction of arm movement. The meta-analysis was performed by Stata 12.0. Results: Five RCTs and three cohort studies that met the inclusion criteria were included in this meta-analysis. It was found that when compared with no axillary lymph node dissection (ALND) group, ALND did not significantly improve the OS (hazard ratio (HR)=1.01, 95% CI: 0.96 similar to 1.07, P= 0.662), DFS (HR= 0.96, 95% CI: 0.80 similar to 1.15, P=0.644) and local recurrence (OR=2.32, 95% CI: 0.91 similar to 5.89, P=0.78). However, subgroup analysis based on the status of SLN showed that patients with macrometastasis of SLN (defined as tumor deposits> 2 mm) had a higher recurrence rate (OR= 5.96, 95% CI: 1.33 similar to 26.70, P=0.02). The incidence of postoperative complications including lymphedema, sensory neuropathy, motor neuropathy and infection in the no-ALND group was significantly lower than that in the ALND group (P<0.05 or 0.01). Conclusion: ALND could be omitted in patients with T1-2 primary breast cancer and without palpable lymphadenopathy.