Genetic polymorphisms in the cytochrome P450 1A1 and 2E1 genes, smoking, drinking and prostate cancer susceptibility: A case-control study in a Han nationality population in Southern China

Aim: To investigate the association among the polymorphisms of the cytochrome P450 1A1 and 2E1 genes, smoking, drinking and the risk of prostate cancer (PCa) in a Han nationality population in Southern China. Methods: A case–control study including 225 PCa patients and 250 age‐matched controls was conducted. The six polymorphic sites of the CYP 1A1 and CYP2E1 genes were analysed by polymerase chain reaction restriction fragment length polymorphism (PCR‐RFLP) or allele‐specific PCR technique using genomic DNA isolated from peripheral blood lymphocytes. Results: We found that the CYP1A1 Val/Val genotype significantly increased the risk for PCa (OR, 2.26; 95% CI, 1.09–4.68). In contrast, the CYP2E1 C1/C2 (OR, 0.67; 95% CI, 0.46–0.99) or C2/C2 genotype (OR, 0.31; 95% CI, 0.10–1.00) significantly decreased the risk. Furthermore, the individuals carrying the CYP1A1 Val allele and the CYP2E1 C1/C1 genotype showed the highest risk (OR, 2.50; 95% CI, 1.45–4.29). Though there was no significant difference with smoking history (P = 0.237) or drinking habit (P = 0.499) between cases and controls, a deep smoking habit (OR, 2.02; 95% CI, 1.28–3.17) and heavy smoking history (OR, 1.61; 95% CI, 1.04–2.50) significantly increased the susceptibility of PCa after stratification by smoking method and accumulative smoking amount. Moreover, both the CYP1A1 Val allele (OR, 2.82; 95% CI, 1.49–5.35) and CYP2E1 C1/C1 genotype (OR, 2.57; 95% CI, 1.31–5.02) had obvious interaction with heavy smoking history that significantly raised the risk. We also discovered a significant interaction between the CYP2E1 C1/C1 genotype and drinking (OR, 1.85; 95% CI, 1.04–3.28). Conclusions: Individuals carrying the CYP1A1 Val allele or the CYP2E1 C1/C1 genotype with a smoking or drinking habit were at increased risk of PCa, which also showed a positive correlation with exposure dose of tobacco.