OBJECTIVETo explore the interaction between inheritance and environment with the aid of research on the genetic modes of hepatocellular carcinoma (HCC).

METHODSA genetic epidemiological study of HCC was conducted based on the methods of Penrose, simple segregation and Falconer for 100 proband pedigrees from HBsAg positive cohort. The proband samples came from a cohort of 90,00 people who were followed for 8 years. Analyses on genetic modes were carried out and heritability was calculated through the comparison of the proband pedigrees incidence frequency with incidence frequencies of the cohort and general population.

RESULTSThe incidence frequency of first-degree relatives was 4.0%, higher than what was seen in the general population incidence frequency (0.44%) and the cohort (1.03%). A familial aggregation of HBsAg carriers and a strong positive correlation between HBsAg carrier status and HCC were noticed (OR = 8.44, 95% CI: 3.37-20.06, P < 0.001). A ratio of the incidence frequency among siblings to the incident frequency among general population (s/q) approached 1/q(1/2) by Penrose method, but simple segregation did not show agreement with single-gene inheritance. The heritability from positive cohort was 42% +/- 6% (P < 0.05), compared with the heritability (59% +/- 7%) of general population. When the effect of the HBsAg was under control, the heritability from positive cohort turned to be 29% +/- 8% (P < 0.05), compared with the heritability (47% +/- 7%) of general population.

CONCLUSIONOur findings suggested that HCC followed a multifactorial mode rather than single inheritance. An interaction effect of inheritance and environment on HCC was also noticed.