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

Background: The aim of this meta-analysis is to evaluate the role of sentinel lymph node biopsy (SLNB) in patients with microinvasive breast cancer. Methods: We 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. Findings: A 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. Interpretation: The 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. (C) 2013 Elsevier Ltd. All rights reserved.