Dietary intake of folate and alcohol, MTHFR C677T polymorphism, and colorectal cancer risk in Korea

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.

Section: Characteristics Of Studiesmentioning

confidence: 99%

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

Yang

Zhang²,

Liu³

et al. 2012

“…Table 2 listed the main results of this meta-analysis. 13 studies determined the relationship between the C677T polymorphism and colon cancer risk (Slattery et al, 1999;Keku et al, 2002;Toffoli et al, 2003;Kim et al, 2004;Jiang et al, 2005;Wang et al, 2006;Curtin et al, 2007;Cao et al, 2008;Komlosi et al, 2010;Promthet et al, 2010;Jokic et al, 2011;Kim et al, 2012;Rai et al, 2014). The total sample size for patients with colon cancer and healthy controls was 5 386 and 8 017, respectively.…”

Section: Study Characteristicsmentioning

confidence: 99%

“…Previous studies investigated the association between MTHFR C677T polymorphism and colon carcinoma risk, but the impact of MTHFR polymorphism on colon carcinoma was still conflicting due to inconsistent findings in individual studies (Slattery et al, 1999;Keku et al, 2002;Toffoli et al, 2003;Kim et al, 2004;Jiang et al, 2005;Wang et al, 2006;Curtin et al, 2007;Cao et al, 2008;Komlosi et al, 2010;Promthet et al, 2010;Jokic et al, 2011;Kim et al, 2012;Rai et al, 2014). Therefore, the current meta-analysis aimed to quantify the strength of the association between MTHFR polymorphisms and colon cancer risk by pooling data from all available casecontrol studies.…”

Section: Introductionmentioning

confidence: 99%

5,10-Methylenetetrahydrofolate Reductase Polymorphisms and Colon Cancer Risk: a Meta-analysis

Fang

Xu²,

Huang³

et al. 2014

Previous studies investigating the association between 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and colon cancer risk have generated conflicting results. The aim of our meta-analysis was to clarify the precise association. A systematic literature search was conducted to identify all relevant studies. Pooled odds ratio (ORs) with 95% confidence interval (CI) were used to estimate the strength of the association. In this meta-analysis, a total of 13 articles, involving 5,386 cases and 8,017 controls met the inclusion criteria. Overall, a significant association was found between colon cancer risk and the MTHFR C667 polymorphism

“…Perturbations in these pathways can result in multiple molecular effects which contribute to the development and progression of cancer (Jing et al, 2012;Gao et al, 2013). Epidemiological data provides clear evidence that folate plays a critical role in colorectal cancer occurrence either on its own or in concert with folate genetic variants (Roswall et al, 2010;Kim et al, 2012;Liu et al, 2013), although little work exists on C1561T-GCPII as a risk factor for colorectal cancer via alteration to folate metabolism.…”

Section: Introductionmentioning

confidence: 99%

Genetic Variation in Glutamate Carboxypeptidase II and Interaction with Dietary Natural Vitamin C May Predict Risk for Adenomatous Polyp Occurrence

Choi¹,

Yates²,

Martin³

et al. 2015

Self Cite

Background: The C1561T variant of the glutamate carboxypeptidase II (GCPII) gene is critical for natural methylfolylpolyglutamte (methylfolate) absorption, and has been associated with perturbations in folate metabolism and disease susceptibility. However, little is known on C1561T-GCPII as a risk factor for colorectal cancer. Therefore, this study examined whether C1561T-GCPII influences folate metabolism and adenomatous polyp occurrence. Materials and Methods: 164 controls and 38 adenomatous polyp cases were analysed to determine blood folate and plasma homocysteine (Hcy) level, dietary intake of natural methylfolate, synthetic pteroylglutamic acid (PteGlu), vitamin C and C1561T-GCPII genotype. Results: In controls and cases, 7.3 and 18.4 percent of subjects respectively, were found to have the CT genotype, increasing the risk for adenomatous polyp occurrence 2.86 times (95% CI:1.37-8.0, p=0.035). Total dietary folate, methylfolate and PteGlu intake and the level of erythrocyte folate and plasma Hcy did not predict the occurrence of an adenomatous polyp. However, dietary natural vitamin C intake was associated with adenomatous polyp risk within C1561T-GCPII CT genotype subjects (p=0.037). Conclusions: The findings suggest that C1561T-GCPII variation may be associated with risk for adenomatous polyp, and vitamin C may modify risk by interacting with the variant gene, its expression product and/or folate substrates.