MTHFR polymorphisms as prognostic factors in sporadic colorectal cancer.

AIM

Theoretically, individuals having at least one mutant allele present a modified activity of the MTHFR enzyme and low methylation, DNA synthesis-repair respectively, which could imply a higher risk of colorectal cancer. The purpose of this study was to investigate the relations of these mutations with the clinico-pathological aspects of colorectal cancer.

MATERIAL AND METHOD

The study included 69 patients with sporadic colorectal cancer. The relative risk in homozygous patients with a normal allele and for mutations C667T and A1298C, in heterozygous patients with one normal and one mutant allele, and for homozygous patients for the mutant allele was calculated.

RESULTS

C667T and A1298C mutations represent a risk factor for colorectal cancer with an OR (odds ratio) = 2.13 (CI (0.51-8.91)) and 3 (CI(0.3-29.58), respectively, in homozygous patients. These mutations are associated with a more frequent location of lesions at the colon level, OR=2.3 and 2.15 respectively. The incidence of the A1298C mutation was more frequent in stage N0 than N+ (p<0.05), pT2 vs. pT3 (p<0.05), as well as in Dukes stages B and D vs. A or C (p<0.05).

CONCLUSIONS

The results obtained support the hypothesis of an increased colorectal cancer prevalence in patients with one of the MTHFR gene mutations. These patients develop colon cancer more frequently, they present lymph node invasion more rarely, and develop more often distant metastases.