Cytochrome P450 2E1 gene polymorphism and alcohol drinking on the risk of hepatocellular carcinoma: a meta-analysis

The gene polymorphism of Cytochrome P450 2E1 (CYP2E1) is supposed to be associated with cancer susceptibility. Many studies focusing on the Pst I/Rsa I polymorphism of CYP2E1 gene and hepatocellular carcinoma (HCC) risk have been conducted and the results are conflicting. In the current study, a meta-analysis of published studies was performed to assess the association between CYP2E1 Pst I/Rsa I polymorphism and risk to HCC. 11 studies containing 1,178 cases and 1,623 controls were selected to determine whether c2 allele of CYP2E1 gene can increase HCC susceptibility, especially through interacting with alcohol drinking. Using the random effects model, the result indicated that there was no association between CYP2E1 Pst I/Rsa I genotype and HCC risk [odds ratio (OR) 1.03 (95 % confidence interval (CI): 0.76-1.40) for c2 variant allele and OR 0.82 (95 % CI: 0.51-1.31) for c2 homozygotes compared with wild-type homozygotes]. The association between CYP2E1 (c2) variant allele and HCC susceptibility were found when interacting with alcohol [OR 2.88 (95 % CI: 1.25-6.60)]. In conclusion, this meta-analysis results showed that Pst I/Rsa I polymorphism of CYP2E1may slightly increase the risk of HCC and alcohol consumption increases the probability of developing HCC, especially for the carriers of some CYP2E1 alleles. CYP2E1 Pst I/Rsa I polymorphism may contribute to the proportion cases of HCC, which needs further investigations.