Functional RsaI/PstI Polymorphism in Cytochrome P450 2E1 Contributes to Bladder Cancer Susceptibility: Evidence from a Meta-analysis

Background: Cytochrome P450 2E1 (CYP2E1) might be involved in the development of bladder cancer. However, previous studies of any association between CYP2E1 RsaI/PstI polymorphism and bladder cancer risk have yielded conflicting results. In this study, we performed a more precise estimation of the relationship by a meta-analysis based on the currently available evidence from the literature. Method: To assess the effect of CYP2E1 RsaI/PstI polymorphism on bladder cancer susceptibility, a meta-analysis of 6 available studies with 1,510 cases and 1,560 controls were performed through Feb 2014. Summary odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to estimate the strength of association for CYP2E1 RsaI/PstI polymorphism under different genetic models. Results: When available studies were pooled into the meta-analysis, we found that the C1C2 and C2C2 genotypes of CYP2E1 RsaI/PstI polymorphism significantly decreased bladder cancer risk under different genetic models (heterozygote: OR=0.766, 95% CI=0.613-0.957, P-OR=0.019; homozygote: OR=0.51, 95% CI=0.303-0.858, P-OR=0.011; dominant: OR=0.733, 95% CI=0.593-0.905, P-OR=0.004; recessive: OR=0.565, 95% CI=0.337-0.947, P-OR=0.030). Subgroup analysis indicated that C2C2 genotype was significantly associated with decreased bladder cancer risk under the homozygote genetic model in Caucasians. There was no evidence of heterogeneity or publication bias. Conclusions: The current meta-analysis suggested that the CYP2E1 RsaI/PstI polymorphism might be associated with bladder cancer susceptibility, especially in Caucasians. Further studies are needed to validate the above conclusion.