CYP2E1 PstI/RsaI polymorphism and interaction with alcohol consumption in hepatocellular carcinoma susceptibility: evidence from 1,661 cases and 2,317 controls

Many studies have suggested that cytochrome P450 2E1 (CYP2E1) gene might be involved in the development of hepatocellular carcinoma (HCC). However, the results have been inconsistent. In this study, the authors performed a meta-analysis to clarify the association between Pst I/Rsa polymorphism in the CYP2E1 gene and HCC risk. PubMed and China National Knowledge Infrastructure were searched for eligible publications. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed- or random-effects model. Fifteen studies (1,661 HCC cases and 2,317 controls) were identified for the data analysis. The overall result showed that there was no statistically significant association between CYP2E1 Pst I/Rsa polymorphism and HCC risk (c2/c2 vs. c1/c1, OR = 0.73, 95% CI 0.50-1.06; c1/c2 vs. c1/c1, OR = 1.00, 95% CI 0.76-1.33; c2/c2+ c1/c2 vs. c1/c1, OR = 0.99, 95% CI 0.77-1.26; c2/c2 vs. c1/c2+ c1/c1, OR = 0.73, 95% CI 0.50-1.06). Further stratified analyses indicated that the habitual alcohol drinkers with c2 alleles were more likely to develop HCC (OR = 1.73, 95% CI 1.19-2.51), compared with the non-habitual drinkers with c1 homozygote. The meta-analysis indicated that CYP2E1 Pst I/Rsa polymorphism was not associated with HCC risk, while the interaction between Pst I/Rsa polymorphism and alcohol consumption increased the risk of HCC.