The epidemiology of hepatocellular carcinoma.

Documentation of the wide geographical variation in the incidence of hepatocellular carcinoma has led to the clear identification of several risk factors. These include chronic infection with hepatitis B and/or hepatitis C and exposure to aflotoxin. All these agents may cause hepatocellular carcinoma but how they interact and how they are related to cirrhosis, which underlies most cases, remains an area of active research. Intervention programmes, most notably immunization against hepatitis B, are now under way and a marked decrease in incidence of hepatocellular carcinoma can be anticipated in the early part of the next century.