Purpose: This study aimed to explore the relationship between TNF-α-308G/A polymorphism (rs1800629) and the risk of colorectal cancer (CRC) by meta-analysis.
Methods: Articles on exploring the relationship between TNF-α-308G/A polymorphism and CRC risk were searched from PubMed, Web of Science and Embase. The timeliness and authority of the included articles were evaluated. 95% confidence interval (95% CI) and odds ratio (OR) were calculated using fixed effect model or random effect model. Subgroup analysis was performed based on the ethnicity, source of control and method of genotyping. Finally, meta-analysis was conducted using STATA 12.0 software.
Results: Sixteen articles were selected (all case-control studies) with 3391 CRC patients and 3995 normal individuals (controls). No significant correlation was found between TNF-α-308G/A polymorphism and CRC risk (dominant gene model, OR=0.96, 95%CI, 0.86-1.07, p>0.05; recessive gene model, OR=1.32, 95%CI, 0.99-1.76, p>0.05; homozygous model, OR=1.28, 95%CI, 0.95-1.72, p>0.05;heterozygous model, OR=0.92, 95%CI, 0.82-1.04, p>0.05; allele model, OR=0.96, 95%CI, 0.87-1.07, p>0.05). Besides, we did not observe remarkable correlation in subgroup analysis of Asian and Caucasian CRC patients. Subgroup analysis of source of control showed no significance in hospital-based subgroup. However, TNF-α-308G/A polymorphism could reduce CRC risk in population-based subgroup (dominant gene model, OR=0.80, 95%CI, 0.63-1.00, p<0.05; heterozygous model, OR=0.76, 95%CI, 0.60-0.97, p<0.05; allele model, OR=0.80, 95%CI, 0.66-0.98, p<0.05). On the contrary, TNF-α-308G/A polymorphism could increase CRC risk in subgroup analysis of method of genotype detected by PCR-RFLP (recessive gene model, OR=1.77, 95%CI, 1.10-2.86, p<0.05; homozygous model, OR=1.79, 95%CI, 1.10-2.89, p<0.05).
Conclusions: Our analysis indicated no significant correlation between TNF-α-308G/A polymorphism (rs1800629) and CRC risk.