Association du polymorphisme de la méthylènetétrahydrofolate réductase C677T avec le risque de cancer colorectal sporadique

Colorectal cancer (CRC) is a major global public health problem. Folate metabolism is involved in DNA synthesis, repair and methylation. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. Common MTHFR C677T polymorphism was correlated to CRC. This case-control study was conducted to analyze the association between this polymorphism and the risk of sporadic CRC in a Moroccan population. The study involved 76 patients with sporadic colorectal cancer confirmed histologically and 182 patients (control group) without a history of cancer. Deoxyribonucleic acid (DNA) was isolated from peripheral blood and genotypes were determined using PCR-RFLP. The risk of association was estimated using odds ratio (OR) with 95% confidence interval. Genotype frequency of MTHFR in patients and in the control group was CC 34.1%, CT 56.6%, TT 9.21%, CC 51.6%, CT 42.8% and TT 6% respectively. CT genotype and its combination with TT genotype and allele T were associated with an increased risk of CRC and with an OR of 2.02 (with 95% confidence interval [CI]: 1.14-3.58, p = 0.01), 2.05 (95 % CI: 1.18-3.58, p= 0.01) and 1.61 (95% CI: 1.07-2.40, p=0.02). Homozygous TT weren´t a protection factor in our study, with an OR of 2.30 (95% CI: 0.81-6.52, p = 0.11). There was a statistically significant association between the MTHFR C677T variant and the risk of occurrence of sporadic colorectal cancer in the studied population.