MTHFR C677T and A1298C polymorphisms and oral cancer risk: an updated meta-analysis

Previous studies have investigated that two functional polymorphisms (C677T, A1298C) of methylenetetrahydrofolate reductase (MTHFR) gene may play an vital role in head and neck carcinogenesis, especially oral cancer, however, the association among these two single nucleotide polymorphisms (SNPs) in MTHFR gene and the susceptibility of oral cancer (OC) was ambiguous and inconsistent. The objective of our current study was to conduct an update meta-analysis to evaluate the association among MTHFR C677T, A1298C SNPs and OC risk. We performed an updated meta-analysis of nine papers involving association between OC and MTHFR gene three polymorphisms. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Both in the whole and subgroup analysis, no significant association was found between C677T polymorphism and OS susceptibility. However, for A1298C polymorphism, decreased association was detected in the recessive genetic model (OR = 0.62, 95% CI = 0.41-0.92, P = 0.918), moreover, in the subgroup analysis by ethnicity, the similar result was observed (OR = 0.62, 95% CI = 0.41-0.95, P = 0.485). To our regret, neither C677T nor A1298C SNP was related to the tumor stage. Results from our current update analysis suggested that A1298C polymorphism in MTHFR gene were associated with OC risk.