Second, MTHFRC677T polymorphism, which affects the blood homocysteine levels, was used as an instrumental variable to calculate the risk and estimate the association of gastric cancer with this single nucleotide polymorphism (SNP).
Our data suggested that rs114673809, which is located at the miR-214 binding site in the 3'-UTR of MTHFR, may play an important role in the development of gastric cancer in a Chinese Han population.
After shrinkage and adjusting for potential confounding factors, we found positive associations between MTHFRrs1801133 and stomach cancer (any T versus C/C, SB odds-ratio [SBOR]: 1.79, 95% posterior limits: 1.18, 2.71) and liver cancer (SBOR: 1.51, 95% posterior limits: 0.98, 2.32).
This meta-analysis supports an association between the MTHFRC677T polymorphism and increased risk of esophageal and stomach cancer, especially among Asians.
The meta-analysis suggests that the polymorphism of MTHFRC677T but not MTHFRA1298C confers a risk effect on the development of gastric cancer among Asians and Caucasians, which provides a new insight into the gastric cancer pathogenesis.
Our study suggests a protective role of MTHFR 677TT and high folate intake against gastric cancer, and the effect of the MTHFR C677T genotype may differ by H. pylori infection, folate consumption, and tumor site.
Polymorphism of methylenetetrahydrofolate reductase gene is associated with response to fluorouracil-based chemotherapy in Chinese patients with gastric cancer.
Associations of P16, MGMT, hMLH1 and hMLH2 with gastric cancer and their relation with MTHFR status in gastric patients who were confirmed with pathological diagnosis were assessed.
However, MTHFR c.677C>T homozygosity with lifelong hyperhomocysteinemia and hence hypomethylation associate with increased risk of esophagus and gastric cancer, and with decreased risk of colorectal cancer.
Cox regression revealed ypT category (P = 0.001) and lymphatic vessel invasion (P = 0.03) to be independent prognostic factors for esophageal cancer, and histopathological response (P = 0.01), MTHFR variant (rs1801131, P = 0.002), and ypN category (P = 0.02) to be prognostic factors for gastric cancer.
The MTHFRC677T frequencies of CC, CT, and TT genotypes were 35.2%, 47.5%, and 17.3% among stomach cancer, 34%, 50.5%, and 15.5% in colorectal cancer, and 31.8%, 50.7%, and 17.5% in the controls, respectively.
Previous data on vitamins B2 and B6 and genetic polymorphisms other than those involving MTHFR as risk factors for gastric cancer (GC) are sparse and inconsistent.
We retrospectively analyzed the survival impact of estimated folate intake by a food frequency questionnaire and MTHFR and TYMS polymorphisms in 132 patients with advanced gastric cancer who were treated with first-line FU-based chemotherapy.