sentence: All included studies must meet the following criteria : ( 1 ) evaluation of these three microRNA polymorphisms ( miR-499 rs3746444 , miR-196a rs11614913 and miR-146a rs2910164 ) and BC risk ; ( 2 ) case-control studies ; ( 3 ) sufficient genotyping data that could be used to calculate odds ratios ( ORs ) and 95 % confidence intervals ( CIs ) ; ( 4 ) all the breast cancer subjects in case groups must be pathologically confirmed .