Significant association between functional microRNA polymorphisms and head and neck cancer susceptibility: a comprehensive meta-analysis.

Molecular epidemiological studies have showed a closer association between microRNA polymorphisms with and head and neck cancer (HNC) risk. But the results of these studies were inconsistent. We performed this meta-analysis to clarify the associations between microRNA polymorphisms and HNC risk. Four electronic databases (PubMed, Embase, CNKI, and Wanfang) were searched. Odds ratios (ORs) with 95% confidence interval (CIs) were calculated to assess the association between microRNA-146a rs2910164 G > C, microRNA-196a2 rs11614913 C > T, microRNA-149 rs2292832 C > T, microRNA-499 rs3746444 A > G polymorphisms and HNC risk. Heterogeneity, publication bias and sensitivity analysis were conducted to guarantee the statistical power. Overall, 11 selected articles involving 16100 subjects were included in this meta-analysis. Significantly increased risk between microRNA-146a rs2910164 G > C polymorphism and HNC risk were observed in Caucasian population (GC vs. GG: OR = 1.31, 95%CI = 1.01-1.68; GC + CC vs. GG: OR = 1.26, 95%CI = 1.02-1.57). For microRNA-196a2 rs11614913 C > T, similarly increased risk were also found in Asian population (T vs. C, OR = 1.14, 95%CI = 1.04-1.25; TT vs. CC, OR = 1.33, 95%CI = 1.09-1.61; CT + TT vs. CC OR = 1.32, 95%CI = 0.99-1.76; TT vs. CC + CT, OR = 1.14, 95%CI = 0.99-1.33). In addition, no significant association was detected between microRNA-149 rs2292832 C > T and microRNA-499 rs3746444 A > G polymorphism and HNC risk. This meta-analysis demonstrates that microRNA polymorphisms are associated with HNC development based on ethnicity diversity.

Meta-analysis of the CYP1A2 -163C>A polymorphism and lung cancer risk.

Many published studies have concerned associations between the CYP1A2 -163 C>A polymorphism and risk of lung cancer, but the results have been inconsistent. Therefore, we performed a meta-analysis to obtain a more precise estimate. We searched the PubMed database up to March 1, 2013 for relevant cohort and case-control studies. Supplementary search was conducted manually by searching the references of the included studies and relevant meta-analyses. A meta-analysis was performed using RevMan 5.2 software for calculation of pooled odds ratios (ORs) and relevant 95% confidence intervals (CIs) after data extraction. Finally, seven case-control studies and one nested case-control study involving 1,675 lung cancer patients and 2,393 controls were included. The meta-analysis showed that there was no association of CYP1A2 -163 C>A polymorphism with risk of lung cancer overall [(OR=0.89, 95%CI= 0.74-1.07) for C vs. A; (OR=0.73, 95%CI= 0.50-1.07) for AA vs. CC ; (OR=0.82, 95%CI= 0.62-1.09) for AC vs. CC; (OR=0.79, 95%CI= 0.58-1.07) for (AC+AA) vs. CC; and (OR=0.87, 95%CI= 0.67-1.13) for AA vs. (CC+AC)]. Subgroup analysis indicated that there was an associationbetween CYP1A2 -163C>A polymorphism and lung cancer risk for population-based controls, a trend risk for SCCL (squamous cell carcinoma of lung) and Caucasians. These results suggested that -163 C>A polymorphism is likely to be associated with risk of lung cancer compared with population-based controls.