The TNF-alpha-238 polymorphism and cancer risk: a meta-analysis

Abstract

Background and objectives: Tumor necrosis factor-α (TNF-α) plays a very important role in the development and progress of cancer. Some TNF-α polymorphisms have been confirmed to increase cancer risks; however, the association between TNF-α-238 polymorphism and cancers remains controversial and ambiguous. The aim of this study is to explore a more precise estimation of its relationship with cancer using meta-analysis.

Methods: Electronic searches of several databases were conducted for all publications on the association between this variant and cancer through March 2011. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to access the strength of this association in the random-effect model.

Results: Thirty four studies with 34,679 cancer patients and 41,186 healthy controls were included. This meta-analysis showed no significant association between TNF-α-238 polymorphism and cancers (AA+GA vs GG: OR = 1.09, 95%CI = 0.88-1.34). In Caucasian and Asian subgroups, OR values (95% CI) were 1.14 (0.91-1.43) and 0.97 (0.58-1.61), respectively. In the subgroups of cancer type, no significant association was detected. The sensitivity analysis further strengthened the validity of these negative associations. No publication bias was observed in this study.

Conclusions: No significant association was found between the TNF-α-238 polymorphism and the risk for cancer.

Figure 1. ORs and 95% confidence interval (CI) of cancer according to TNF-α-238 polymorphism in 34 studies using random-effect model.

AA+GA, AA and GA genotypes of TNF-α-238 polymorphism; GG, GG genotype of TNF-α-238 polymorphism; ORs, odds ratios.

Figure 2. Funnel plots analysis to detect publication bias.

Each point represents an independent study for the indicated association.