MGMT Leu84Phe gene polymorphism and lung cancer risk: a meta-analysis

Many studies have examined the association between the MGMT Leu84Phe polymorphism gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. The PubMed and CNKI database was searched for case-control studies published up to Nov. 2013. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 7 studies, comprising 3,094 lung cancer cases and 4,216 controls, were included. Overall, for (Phe/Phe+Phe/Leu) versus Leu/Leu, the pooled OR for all studies was 1.08 (95% CI = 0.97-1.21 P = 0.518 for heterogeneity); for Phe/Phe versus Leu/Leu and Phe versus Leu, the pooled OR was 1.10 (95% CI = 0.99-1.21 P = 0.445 for heterogeneity) and 1.46 (95% CI = 1.05-2.02 P = 0.352 for heterogeneity), respectively. In the stratified analysis by ethnicity, significantly risks were found among Caucasians not in Asians. This meta-analysis suggests that the MGMT Leu84Phe polymorphisms are associated with lung cancer risk among Caucasians not in Asians.