Association study between genetic polymorphisms in folate metabolism and gastric cancer susceptibility in Chinese Han population: A case-control study

Background: Gastric cancer (GC), the second leading cause of cancer mortality behind lung cancer worldwide, is caused by both genetic and environmental factors. In this study, we evaluated the association between the genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR), methionine synthesis reductase (MTR), and methyltransferase reductase (MTRR) genes and ischemic stroke risk in Chinese population.

Methods: A case-control study was conducted including 681 patients with GC and 756 healthy controls. Chi-squared test/Fisher's exact test and genetic model were used to evaluate associations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression.

Results: In the allele model, using the chi-square test, we found that the rs1532268 in MTRR with a minor allele T was significantly associated with increased risk of GC (OR = 1.24, 95% CI, 1.00-1.53; p = 0.048). In the genetic model analysis, we identified that the single-nucleotide polymorphism of the rs1801133 in MTHFR could increase the GC risk in the recessive model (OR = 1.31, 95% CI, 1.01-1.70; p = 0.042) and log-additive model (OR = 1.19, 95% CI, 1.02-1.38; p = 0.025). In MTHFR, a strong linkage of rs2274976 and rs1801133 was detected. The haplotype "GC" in the MTHFR gene was found to prominently increase the risk of GC (OR = 1.26, 95% CI: 1.07-1.47; p = 0.005). Other haplotypes did not display the correlativity.

Conclusion: This study suggested that MTR and MTHFR polymorphisms may contribute to increase the risk of GC.