Association of MTHFR C677T and SHMT1 C1420T with susceptibility to ESCC and GCA in a high incident region of northern China

To assess the association between the C to T transition in the methylenetetrahydro folate reductase gene (MTHFR C677T) and the C to T transition in the serine hydroxymethyltransferase(1) gene (SHMT (1) C1420T) and the increased risk of carcinogenesis of esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA) in a population of high incident region of Northern China. The polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism and PCR-confronting two-pair primers analysis respectively among 1051 cancer patients (584 ESCC and 467 GCA) and 540 healthy controls. The MTHFR 677T/T genotype significantly increased susceptibility to both ESCC and GCA compared with the C/C genotype, the adjusted OR was 2.13 (95% CI = 1.50-3.02) and 1.28 (95% CI = 1.07-1.53, respectively. For the SHMT (1) C1420T polymorphism, the C/C genotype was significantly associated with the increased risk of ESCC and GCA, compared with the C/T genotype (the adjusted OR = 1.43 and 1.35, 95% CI = 1.02-2.00 and 1.11-1.63, respectively). The interactive influence of the MTHFR and SHMT1 polymorphisms in the risk of ESCC and GCA was also observed. The association between the MTHFR C677T and SHMT1 C1420T polymorphisms and the risk of ESCC and GCA was demonstrated.