Hepatocellular carcinoma and its risk factors--their annual changes and effects on the age at onset.

A retrospective case-control study was carried out on patients with hepatocellular carcinoma (HCC) admitted between 1976 and 1985 to analyze the relationship between the cancer and risk factors. The following conclusions were reached: 1) the positive rate of Hepatitis B surface (HBs) antigen among the HCC patients decreased from 41% in the period 1976-1980 to 19% in the period 1981-1985. However, the risk of the patients positive for the antigen for HCC was higher in the second period (1:18.7) than in the first period (1:12.8), 2) drinking not only enhanced the risk for HCC 2.7 times, but also accelerated the onset of HCC by about 5 years, 3) blood transfusion enhanced the risk for HCC; HCC occurred in about 20 years on average after blood transfusion in the patients negative for the hepatitis B virus (HBV) and drinking history, and 4) smoking was suggested to be less related to the onset of HCC.