A functional polymorphism rs11614913 in microRNA-196a2 is associated with an increased risk of colorectal cancer although not with tumor stage and grade.

A C/T polymorphism (rs11614913) was identified in the microRNA (miRNA) 196a2 (miR-196a2) gene and was implicated in the susceptibility to cancer. Numerous studies have investigated its association with the risk of colorectal cancer (CRC). However, the results were inconsistent and inconclusive. The present meta-analysis was conducted based on the results of six published case-control studies comprising 1,754 cases and 2,430 controls (up to November, 2012). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for the allelic and genotypic comparisons following the co-dominant, dominant and recessive genetic models. The Chi-square-based Q-test was used to assess heterogeneity. Egger's test and inverted funnel plots were used to investigate publication bias. Subgroup analysis was also performed. The results demonstrated that almost all the genetic models (except the model of CT vs. TT) indicated a significant association between rs11614913 polymorphism and CRC risk. The subgroup analysis in an Asian population also demonstrated similar results. However, there was no significant association of miR-196a2 rs11614913 polymorphism with the clinical characteristics of CRC patients. Our results confirmed the association of the polymorphism rs11614913 with the risk of CRC, but not with tumor stage and grade.