OBJECTIVETo study the relationship between esophageal cancer (EC) and the ingestion of folate, methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in Kazakh area, Xinjiang.

METHODSA 1:2 matched case-control study was adopted. 120 cases diagnosed as esophageal cancer were collected with 240 population-based and hospital-based controls were selected by the same sex, same nationality and each pair's ages were permitted to differ within 5 years. MTHFR genotypes were detected by polymeerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the conditional logistic regression model was performed in this study.

RESULTSData showed that the ingestion of folate was related to EC in Kazakh (chi2 = 7.868, nu = 1, P < 0.01) with OR: 0.519 (95% CI:0.329-0.821) while more folate intake appeared to be the protective factor of EC in Kazakh. The MTHFR C677T genotype frequencies of EC group was different from the control group (chi2 = 15.823, nu = 1, P < 0.01). The individuals with 677CT, TT genotype had a 2.613-fold (95% CI: 1.628-4.194) increased risk of developing EC, compared to those who had 677CC genotype. Data from Interaction Analysis showed that more folate intake could reduce the incidence of esophageal cancer to the individuals who carried the MTHFR 677CT or TT genotypes.

RESULTSfrom multivariate conditional logistic regression analysis showed that: unsanitary drinking water, irregular eating, prefer eating peppery food, engorgement, crusted rice or wheat, having history of stomach or esophagus illness, carrying MTHFR 677CT or TT genotypes were risk factors of esophageal cancer while taking in more folate was the protective factor of EC.

CONCLUSIONLacking of folate intake were mainly risk factor and the polymorphisms of MTHFRC677T gene were susceptibility factor of esophageal cancer in Kazakh in Xinjiang.