MTHFR C677T Polymorphism and Colorectal Cancer Risk in Asians, a Meta-analysis of 21 Studies

Abstract

Background: Previous studies concerning the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and colorectal cancer risk in Asian populations generated conflicting results. A meta-analysis was therefore performed to allow a more reliable estimate of any link. Methods: Relevant studies concerning the association between the MTHFR C677T polymorphism and risk of colorectal cancer were included into this meta-analysis. The quality of the studies was assessed according to a predefined scale. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for this gene-disease association using fixed or random effect models according to the heterogeneity between included studies. Results: Finally, 21 studies with a total of 6692 cases and 8266 controls were included. Meta-analyses showed that there was an obvious association of the MTHFR 677T allele with decreased risk of colorectal cancer (OR = 0.91, 95%CI=0.85-0.98, P=0.011). Subgroup analyses by country further identified this association, with dietary folate as the main source of heterogeneity. Conclusion: The MTHFR 677T allele is associated with a lower risk of colorectal cancer in Asian populations, and there is effect modification by population plasma folate.

Association between folate metabolism-related polymorphisms and colorectal cancer risk

“…Previously, a comprehensive meta-analysis demonstrated that the MTHFR 677T allele is associated with reduced risk of CRC (13). In addition, Yang et al (14) conducted a meta-analysis incorporating 21 studies of the Asian population and obtained similar results. Although the mechanism responsible for the association between the MTHFR 677C>T polymorphism and CRC risk remains unclear, it is possible that MTHFR variants increase the level of 5,10-methylenetetrahydrofolate available for DNA synthesis, thereby protecting against CRC.…”

Personalized Hypertension Management in Practice

“…The loss of function gene variant C677T (rs1801133), within the MTHFR gene, has been associated with elevated homofuture science group Personalized hypertension management in practice Review cysteine, coronary artery disease, cancer and hypertension in population studies. However ethnicity and diet appear to be strong confounders and these results have not been consistently reproduced [16][17][18][19].…”

Cáncer de colon y su relación con la fortificación de ácido fólico

“…En otro metaanálisis publicado el año 2013 23 , se determinó asociación entre el polimorfismo C1420T en el gen de la serina hidroximetiltransferasa citosólica (SHMT1) y riesgo de cáncer colorrectal. Se evaluaron los datos individuales sobre 5.043 casos y 6.311 controles de 15 estudios de casos y controles publicados.…”

“…Los autores concluyeron que en general no hubo asociación, pero sugirieron efectos de geografía específica del polimorfismo SHMT1 que hacen a europeos susceptibles, pero no a estadounidenses. El nivel de folato parece mostrar una asociación inversa de este polimorfismo con el cáncer colorrectal 23 .…”