Objective: To study the relationship between familial clustering of hepatocellular carcinoma (HCC) and the polymorphism of cytochrome P450 2El gene (CYP2E1) as well as of other relevant risk factors to the cancer.
Methods: Peripheral blood samples were collected from 91 members of 10 HCC clustering families and 102 of 10 control families, among Zhuang population, in Guangxi. The area had been with high incidence rate of HCC. Genotypes and allele frequencies of CYP2E1 Rsa I site were determined by polymerase chain reaction, combined with restriction fragment length polymorphism method (PCR-RFLP). Serum HBsAg was tested by means of ELISA. Data on relevant risk factors of the cancer were collected as well, through a unique questionnaire.
Results: Frequencies of c1/c1 and c1/c2 genetypes of CYP2E1 Rsa I site were 63.7% and 36.3%, respectively, in the members of families with cancer clustering phenomena. In the members of the control families, these two rates were 48.0% and 52.0%, respectively (OR = 1.901, 95% CI: 1.067-3.387). Difference of genotypes frequencies of CYP2E1 Rsa I site between the members in these two groups was statistically significant (chi2 = 4.797, P = 0.029). According to the results from non-condition logistic regression analysis, the major risk factors on familial clustering of HCC could be listed as: intake of corns, HBsAg carrying status and CYP2E1 c1/c1 genotype.
Conclusion: The relationship seemed to exist between familial clustering of HCC and the frequencies of polymorphism of cytochrome P450 2E1 gene (CYP2E1). The frequencies of CYP2E1 Rsa I site were neither the only nor the major factor, causing the familial clustering phenomenon of cancer. More possible, it was the affect of syntheses with the involvement of multiple factors.