Quantitative assessment of the association between miR-196a2 rs11614913 polymorphism and gastrointestinal cancer risk

Published data on the association between miR-196a2 rs11614913 polymorphism and risk of gastrointestinal (GI) cancers are inconsistent among studies. To clarify the association, we performed a comprehensive literature search and a meta-analysis. We searched multiple databases to identify genetic association studies investigating the effect of miR-196a2 rs11614913 polymorphism on GI cancers with the last report up to January 18, 2012. The odds ratio (OR) and its 95 % confidence interval (95 % CI) were calculated to assess the strength of association. A total of 13 studies including 4,947 cases and 5,642 controls based on the search criteria were involved in this meta-analysis. In the overall analysis, it was suggested that variant C allele of miR-196a2 rs11614913 polymorphism could significantly increase risk of GI cancers in different genetic models (C vs T: OR = 1.17, 95 % CI = 1.07-1.28, P = 0.0008; CT + CC vs TT: OR = 1.26, 95 % CI = 1.08-1.48, P = 0.004; CC vs CT + TT: OR = 1.23, 95 % CI = 1.08-1.39, P = 0.002; CC vs TT: OR = 1.55, 95 % CI = 1.24-1.94, P = 0.0001; CT vs TT: OR = 1.20, 95 % CI = 1.02-1.40, P = 0.03). When stratified by ethnicity, we found a significant association in Asian population, as well as Caucasian population. When stratified by cancer types, we found a significant association in colorectal cancer, as well as esophageal cancer. We did not find a significant association between miR-196a2 rs11614913 polymorphism and hepatocellular carcinoma risk. For gastric cancer, a significantly increased cancer risk was observed only in homozygote comparison. This meta-analysis demonstrates that miR-196a2 rs11614913 polymorphism is significantly associated with risk of GI cancers.