Genetic Polymorphisms of Methylenetetrahydrofolate Reductase and Susceptibility to Colorectal Cancer

Objectives: To study the relation between genetic polymorphisms of methylenetetrahydrofolate reductase(MTHFR) C677T or A1298C and the susceptibility of colorectal cancer.
Methods: We conducted a case-controlstudy with 315 cases of colorectal cancer and 371 population-based controls in Jiangsu province, China. Theepidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of thesubjects. MTHFR C677T and A1298C genotypes were detected by PCR-RFLP method.
Results: (1) When menand women were assessed together, the frequencies of the MTHFR C677T and A1298 genotypes or their alleleswere not significantly different between controls and colon cancer or rectal cancer cases. No significant relationwas observed between MTHFR C677T or A1298C polymorphisms and colon or rectal cancer susceptibility. (2)Among males, individuals who had MTHFR C677T T/T genotype were at a significantly higher risk of developingcolon cancer (age-, residence-, smoking, alcohol drinking-, tea consumption-adjusted OR=2.15, 95%CI: 1.07-4.33) compared with those who had C677T C allele. Individuals who had C677T T/T and A1298C A/A genotypeswere at an increased risk of developing colon cancer (adjusted OR=2.64, 95%CI: 1.20-5.81) compared withthose with C677T C allele and A1298C A/A genotypes among males. On the contrary, individuals who hadC677T T/T and A1298C A/A genotypes were at an decreased risk of developing rectal cancer (adjusted OR=0.47,95%CI: 0.22-1.03).
Conclusions: These results in the present study suggested that polymorphisms of the MTHFRC677T could influence susceptibility to colon or rectal cancer and that there was a coordinated effect betweenMTHFR A1298C A/A and C677T T/T genotypes among males.