Objective: In order to study the relation between polymorphisms of methylenetetrahydrofolate reductase C677T (MTHFR) and susceptibility of stomach cancer (SC).
Methods: We conducted a case-control study with 107 cases of SC and 200 population-based controls in Huaian city of Jiangsu province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. MTHFR genotypes were detected by PCR-RFLP method.
Results: (1) The frequency of MTHFR variant genotypes (C/T + T/T) among the cases (79.4%) was significantly higher than the controls (68.5%) (P = 0.041 6); the crude OR for SC was 1.78 (95% CI: 0.99 - 3.22). After adjustment for sex and age, the OR for SC was 1.89 (95% CI: 1.08 - 3.32). (2) Subjects who had MTHFR variant genotypes and having smoking habit were at a significantly higher risk of developing SC (OR = 7.72, 95% CI: 2.23 - 26.79) compared with those who had wild-type homozygotes (C/C) genotype and no smoking habit. Individuals who had variant genotypes and who had habit of frequent alcohol drinking were at an increased risk of developing SC (OR = 3.08, 95% CI: 1.30 - 7.23) compared with those with C/C genotype and low consumption of alcohol. As compared with subjects with C/C genotype and low consumption of alcohol and no smoking habit, individuals who had variant genotypes and who had habits of frequent alcohol drinking and smoking had 12.96 (95% CI: 2.76 - 70.46) folds risk developing SC.
Conclusions: These results in the present study suggested that the polymorphisms of MTHFR C677T was associated with risk of developing SC, and there was a coordinated effect between MTHFR genotypes and habits of smoking and alcohol drinking in the development of SC.