Methylenetetrahydrofolate reductase 677TT genotype might be associated with an increased lung cancer risk in Asians.

Background: The association between methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism and lung cancer risk has been studied in various populations with conflicting results. The aim of this study was to assess the association strength by a meta-analysis of published studies.

Methods: We searched PubMed and Chinese Biomedical (CBM) databases for relevant literatures published by July 18, 2012. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to assess the strength of the association.

Results: A total of 20 studies comprising 11,653 cases and 12,032 controls were included in the final meta-analysis. Using the random effect model, we found that MTHFR 677TT variant genotype was associated with an increased lung cancer risk (OR=1.26, 95% CI=1.05-1.50, P=0.011 for TT vs. CC; OR=1.19, 95% CI=1.03-1.37, P<0.001 for TT vs. CC+CT; OR=1.11, 95% CI=1.02-1.22, P=0.017 for T allele vs. C allele). In the further stratified analyses, the increased lung cancer risk was found in Asian subjects (OR=1.31, 95% CI=1.01-1.71, P=0.045 for TT vs. CC; OR=1.17, 95% CI=1.00-1.38, P=0.048 for TT vs. CC+CT). There were no evidences for obvious publication bias in the overall meta-analysis and Asian subjects.

Conclusions: MTHFR 677TT genotype might increase the susceptibility of lung cancer, especially in Asians.