Folate Intake, Methylenetetrahydrofolate Reductase Polymorphisms in Association with the Prognosis of Esophageal Squamous Cell Carcinoma

Aim: An epidemiological study was conducted based on an esophageal cancer patient’s cohort to investigate the association of folate intake and MTHFR C677T polymorphism with the prognosis of esophageal cancer in a Chinese population.
Methods: 167 patients aged 37-75 years who had histological confirmed diagnosis of esophageal squamous cell cancer were collected from Jan. 2006 to Jan. 2008. MTHFR genotypes at the C677T site were analyzed by PCR-based RFLP methods, and the folate intake was computed by multiplying the food intake (in grams) and the folate content (per gram) of food in our questionnaire.
Results: We found associations between the prognosis of esophageal cancer and smoking status, T and N stages. Individuals carrying the MTHFR 677CT and TT genotypes showed a shorter survival time than with the CC genotype, with adjusted HRs (95% CI) of 1.20 (0.56-2.15) and 2.29 (1.30-4.28), respectively. Similarly, those carrying MTHFR 677T allele had a 1.86-fold risk of death. A higher folate concentration showed a significant decreased risk of death, with an HR (95% CI) of 0.45 (0.18-0.87). Individuals with high folate intake and the MTHFR 677CC genotype showed a significant decreased risk of esophageal cancer (0.43, 0.25-0.89).
Conclusion: Our findings supports the hypothesis that high folate intake and active MTHFR C677T polymorphism may exert protective roles in the prognosis of esophageal cancer in the Chinese population.