The Role of Tumor Necrosis Factor-α (TNF-α) Polymorphisms in Gastric Cancer: a Meta-Analysis.

PURPOSE: Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine which may play a role in the development of gastric cancer (GC). This study aimed to investigate the association of five TNF-α polymorphisms including TNF-α-857, TNF-α-1031, TNF-α-863, TNF-α-308, and TNF-α-238 polymorphisms with GC risk. METHODS: All eligible case-control studies were collected by searching PubMed, Scopus, and Web of Science. The association of the risk of GC with TNF-α polymorphisms was estimated using odds ratio (OR) and 95% confidence interval (CI). Heterogeneity was assessed via Cochrane's Q and I2 analyses. RESULTS: A total of 46 publications involving 16, 715 cases with GC and 27, 998 controls were recruited. The study revealed a significant association for TNF-α 308 (recessive model: OR = 0.646, P = 0.035), TNF-α-1031 (homozygote model: OR = 1.584, P = 0.027), and TNF-α-857 (homozygote model: OR = 1.760, P = 0.001) polymorphisms with the GC risk. The results of subgroup analysis based ethnicity found a significant association between GC risk and TNF-α-857 polymorphism in Caucasian subgroup (P = 0.005) and TNF-α-1031 polymorphism and GC risk in Asians (P = 0.018). CONCLUSIONS: This study suggested that TNF-α-857 and TNF-α-1031 polymorphisms may be associated with the increased gastric cancer risk.

Are the FTO Gene Polymorphisms Associated with Colorectal Cancer? A Meta-analysis.

BACKGROUND: Colorectal cancer (CRC) is reported to be associated with some gene polymorphisms. However, the effect of the fat mass and obesity associated (FTO) gene on colorectal cancer is not yet clear. This meta-analysis aimed to investigate the association of the FTO gene polymorphism and colorectal cancer. METHODS: PubMed, Web of science, Scopus, and Embase were explored to identify the studies investigating the relationship between rs9939609 and rs17817449 polymorphisms of FTO gene and colorectal cancer, and the published papers from 2000 to 2019 were collected. This meta-analysis was conducted by using a random-effects model for the best estimation of the desired outcomes. RESULTS: In this study, 1528 studies were initially included and five eligible case-control studies including 13,460 cases and 22,578 controls were eligible for further analyses. No significant association was found between risk allele of FTO rs9939609 (OR = 0.98, 0.87-1.1) and rs17817449 (OR = 0.9, 0.79-1.03) polymorphisms and colorectal cancer risk. The subgroup analyses considering the source of the control group and race found no significant association between FTO polymorphisms and the risk of colon cancer. CONCLUSIONS: This study indicated that rs9939609 and rs17817449 FTO gene polymorphisms are not associated with colorectal cancer risk. Individual studies involving different FTO polymorphisms are needed to further evaluation of the associations between the FTO gene and colon cancer.