Polymorphisms of estrogen-metabolizing genes and risk of hepatocellular carcinoma in Taiwan females

Estrogen has been related to the development of hepatocellular carcinoma (HCC). In this molecular epidemiological study, we used logistic regression to compare the genotype frequencies of estrogen-metabolizing genes that are involved in estrogen biogenesis (CYP17), hydroxylation (CYP1A1) and inactivation of the reactive metabolites (catechol-O-methyltransferase, COMT) in HCC patients and control subjects, and determined their relationship with the risk of female HCC. The heterozygous or homozygous variants of high activity CYP17 (A2), high inducibility CYP1A1(m1), and low activity COMT (L) alleles were considered as high-risk genotypes. We found that the risk of HCC was elevated in women harboring either heterozygous or homozygous variants of the CYP1A1 gene and the respective OR (and 95% confidence interval) were 6.61 (1.35, 32.43) and 12.00 (1.73, 83.46). Moreover, we found that the risk of HCC was increased in the female subjects harboring higher numbers of high-risk genotypes, but not in male subjects. The OR for female HCC associated with two putative high-risk genotypes was 12.63 (1.50, 106.37), and the OR for three putative high-risk genotypes was 16.67 (1.82, 152.77). These findings strongly suggest that estrogen play a critical role in female hepatocarcinogenesis.