Abstract
BACKGROUND: Many studies have explored the associations between microRNAs (miRNAs) polymorphisms and lung cancer susceptibility. However, due to their limited statistical sizes, some discrepancies were discovered in these studies. This article summarized eligible studies to identify the roles of miRNAs polymorphisms in lung cancer, and analyzed the associations of polymorphisms in mir-196a2, mir-146a and mir-149 with lung cancer risk respectively. METHODS: The PubMed, Web of Science, ScienceDirect and CNKI databases were searched updated to May 30, 2014. The complete data of three miRNAs polymorphisms for lung cancer were analyzed by odd ratios (ORs) and 95% confidence intervals (CIs). Finally, four studies about mir-196a2 single nucleotide polymorphism (SNP), two studies about mir-146a SNP, three studies about mir-149 SNP were investigated in this analysis. RESULTS: The mir-196a2 polymorphism was revealed to be associated with lung cancer susceptibility (additive model: OR=1.120, 95%CI 1.030 ∼ 1.217, P=0.008; dominant model: OR=1.118, 95%CI 1.039 ∼ 1.357, P=0.011; recessive model: OR=1.133, 95%CI 0.987 ∼ 1.300, P=0.077). However, no relationships were discovered between mir-146a or mir-149 polymorphism and lung cancer risk. CONCLUSIONS: This meta-analysis demonstrates that mir-196a2 SNP influences the susceptibility of lung cancer. Mir-146a and mir-149 SNP do not play a role in lung cancer risk. These findings need more validation by larger studies.