The aryl hydrocarbon receptor (AhR) 1661G > A polymorphism in human cancer: A meta-analysis

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor and plays an important role in the development of cancer. Although there have been many epidemiological studies investigating the relationship between genetic polymorphisms in the aryl hydrocarbon receptor (AhR) gene and human cancer risk, the findings remain conflicting. To derive a more precise estimation of association between the AhR 1661G > A polymorphism and risk of cancer, we performed a systematic meta-analysis based on 11 case–control studies, including 8158 cancer cases and 8336 controls. We used odds ratios with 95% confidence intervals (CIs) to estimate the strength of the association. We also performed subgroup analyses, sensitivity analyses and publication bias analyses. Overall, there was not enough evidence to support the hypothesis that the AhR 1661G > A polymorphism was associated with human cancer risk (homozygote comparison: OR = 0.974, 95% CI = 0.868 to 1.092, P = 0.468 for the heterogeneity test; recessive model comparison: OR = 0.958, 95% CI = 0.859 to 1.068, P = 0.767 for the heterogeneity test). Even after stratified analysis of cancer type and source of controls, no significant association was found. This meta-analysis suggested that the AhR 1661G > A polymorphism does not contribute to the development of cancer in humans. We believe that future refinement of experiments and epidemiological studies will confirm this hypothesis.

► A meta-analysis assessing the association of AHR polymorphism with human cancer risk.
► Subgroup analyses of cancer type and source of controls were performed.
► Lack of association between AHR gene polymorphism and human cancer risk.