Synergism between hepatitis B virus and aflatoxin in hepatocellular carcinoma.

Epidemiological data have suggested that environmental factors play a major role in hepatocellular carcinoma (HCC). Such factors include hepatitis B virus (HBV), infection, chemical carcinogens and parasites. The available data provide compelling evidence of the causative association of HBV with HCC but its exact role has not been defined. Similarly, field studies have indicated the importance of aflatoxin contamination of foodstuffs in areas with high prevalence rates of HCC. The precise role of this mycotoxin has been the subject of debate. The hypothesis that aflatoxin and HBV can interact and cause HCC synergistically has been challenged by those who postulate that aflatoxin merely suppresses cell-mediated immunity, thereby permitting persistence of HBV in the liver.