Evaluating the association of polymorphisms in the HAP1 gene with lung cancer risk: a meta-analysis.

Studies on the relationship of HAP1 polymorphisms (-141 T > G; 1349 T > G) and lung cancer risk to date indicated controversial results. This study was devised to clarify whether the polymorphisms predispose to lung cancer. We searched Embase and PubMed up to March 2014 to identify relevant studies. Data from the eligible studies were independently extracted by two investigators. Pooled odds ratio (OR) was calculated to assess the associations between lung cancer risk and the abovementioned polymorphisms. A total of 15 case-control studies were included in this meta-analysis. Both overall analysis and stratified analysis by ethnicity and smoking status indicated no association between lung cancer risk and the 1349 T > G polymorphism. However, a significantly reduced risk of lung cancer was found among carriers of the GG genotype of the -141 T > G polymorphism, as compared with those of the TT genotype (homozygote model: OR = 0.82, 95% confidence interval (CI) 0.73 to 0.93, P(OR) = 0.002). Likewise, the GG genotype was also found to decrease lung cancer risk compared to the GT + TT genotypes (recessive model: OR = 0.82, 95 % CI 0.73 to 0.92, P(OR) = 0.001). Our meta-analysis suggests that the -141 T > G polymorphism, but not the 1349 T > G polymorphism, may have protective effects for lung cancer.