[Study on the relations between genetic polymorphisms in methylenetetrahydrofolate reductase, methionine synthase and the risk of pancreatic cancer].

Objective: To determine whether genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MS A2756G) were associated with the risks of pancreatic cancer.

Methods: A hospital-based, case-control study consisting of 101 incident pancreatic cancer cases and 337 controls matched on age, sex and race was conducted to investigate the association between polymorphism in MTHFR and MS, and susceptibility to pancreatic cancer. Genotypes of MTHFR C677T, A1298C and MS A2756G were analyzed by polymerase chain reasction-restriction fragment length polymorphism methods.

Results: It was found that multivariate-adjusted odds ratio (ORs; 95% confidence interval) for MTHFR-677CT and 677TT compared with 677CC were 2.17 (1.26 - 3.85) and 3.53 (1.85 - 6.84) respectively, which was in a manner of allele-dose relationship. However, no significant association between the A1298C genotype alone and the risk of cancer was observed which seemed that this polymorphism had a combined effect with the C677T polymorphism. A significant gene-environment interaction was observed between C677T polymorphism and cigarette smoking or alcohol intake. Subjects with variant genotypes who smoked > 17 pack-years had highest risk for developing the cancer, with the OR of 5.58 (2.53 - 12.30). Similarly, the OR (3.27, 1.51 - 7.23) for subjects with variant genotypes of alcohol drinker was significantly higher than that for subjects either having the variant genotype or being drinkers. No association was found between MS A2756G polymorphism and risk of pancreatic cancer in the study.

Conclusion: These findings supported the hypothesis that genetic polymorphisms in MTHFR C677T might contribute to the risk of developing pancreatic cancer.