Purpose: Recent evidence suggests that the rs2910164 variant of miR-146a is associated with the development of certain types of malignancies. Hence, the aim of this study was to investigate the association between this genetic variant and the susceptibility of squamous cell carcinoma (SCC).
Methods: We performed a systematic search using PubMed, EMBASE, ISI Web of Science, Cochrane Central Register of Controlled Trials, ScienceDirect, Wiley Online Library and Chinese National Knowledge Infrastructure (CNKI) databases with the last search updated on November 15, 2014. Studies were pooled and summary odds ratios (ORs) were calculated. Potential sources of heterogeneity were sought out via subgroup analysis.
Results: A total of 12 studies (5192 cases and 9945 controls) were found to be eligible for meta-analysis. Overall, no significant associations were found between miR-146a G/C polymorphism and SCC risk when all studies were pooled into the meta-analysis. In the subgroup analysis by cancer location, statistically significantly increased risks were found for cervical SCC/CSCC (CC vs CG+GG:OR = 0.521, 95% CI=0.412-0.657,p<0.001; CC+CG vs GG:OR=1.583, 95%CI=1.215-2.062,p=0.001); and for skin SCC (GC vs CC+GG:OR=2.533, 95% CI=1.989-3.224, p<0.001). In addition, the C allele and CC genotype of rs2910164 were found to be associated with an inverse risk of nasopharyngeal carcinoma (GG vs CC:OR=0.586, 95% CI=0.405-0.847, p=0.005; CC vs CG+GG:OR=1.496, 95% CI=1.189-1.881, p=0.001). Similarly, CC genotpe of rs2910164 was found to be inversely related to susceptibility of oral SCC (CC+CG vs. GG: OR=0.726, 95% CI=0.607-0.869, p<0.001).
Conclusions: The miR-146a rs2910164 polymorphism is associated with increased risk for cervical and skin SCC. In contrast, rs2910164 in miR-146a is related to decreased risk for nasopharyngeal and oral SCC.