Sentinel lymph node biopsy in patients with microinvasive breast cancer: A systematic review and meta-analysis

BackgroundThe aim of this meta-analysis is to evaluate the role of sentinel lymph node biopsy (SLNB) in patients with microinvasive breast cancer.MethodsWe searched MEDLINE and ISI Web of Science to identify studies including patients with microinvasive breast cancer who underwent SLNB and reported the rate of sentinel-node positivity. We performed proportion meta-analysis using either fixed or random-effects model based on the between-study heterogeneity.FindingsA total of 24 studies including 968 patients met the eligibility criteria. The summary estimate for the sentinel-node (SN) positivity rate was 3.2% (95% Confidence Interval (CI): 2.1%–4.6%), 4.0% (95% CI 2.7%–5.5%), and 2.9% (95% CI: 1.6%–4.6%) for macrometastasis, micrometastasis and isolated tumor cells (ITC) respectively. Significant between-study heterogeneity was observed only in the meta-analysis of ITC positivity rate.InterpretationThe amount of positive sentinel node in patients with proven microinvasive breast cancer is relatively low. As a result, the indications for SLNB in these patients should be probably individualized.