A case-control study on the relationship between methyl-tetra-hydrofolic acid reductase 677 gene polymorphism and the risk of stomach cancer

OBJECTIVE: To explore the relationship between methyl-tetra-hydrofolic acid (MTHFR) 677 gene polymorphism and the risk of stomach cancer. METHODS: A population based case-control study was conducted and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to detect its genotypes. RESULTS: Among cases with stomach cancer, the frequency of C/C, C/T, T/T genotype were 25.8%, 54.6%, 19.6%, compared with controls as 34.5%, 50.9%, 14.6% respectively. Using C/C genotype as reference, the OR of C/T or T/T genotype was 1.52 (95% CI: 1.04 - 2.23). 53.3% C and 46.7% T allele were distributed in stomach cancer cases, while 60.0% C and 40.0% T in controls. The OR for T allele in relation to C allele was 1.31 (1.02 - 1.69) when C allele was used as reference. In addition, the present study showed that MTHFR677 AnyT genotype might interact with smoking, moldy food intake, wheat porridge intake, eating salty food and Hp CagA infection to increase the risk of stomach cancer. No interaction was observed between MTHFR677 AnyT genotype and alcohol drinking or green tea intake. CONCLUSION: MTHFR677 AnyT genotype, might increase the risk of stomach cancer development and the genotype might also interact with other environmental risk factors to increase the risk of stomach cancer.