The role of aflatoxins and hepatitis viruses in the etiopathogenesis of hepatocellular carcinoma: A basis for primary prevention in Guinea-Conakry, West Africa

Aflatoxins and hepatitis B virus (HBV) are major risk factors for hepatocellular carcinoma (HCC) in South-east Asia and Africa, parts of the world where this cancer is most prevalent. Exposure to both factors is endemic, occurring from early in life. There is evidence from both epidemiological studies and animal models that the two factors can act synergistically to increase the risk of HCC, but the underlying cellular and molecular mechanisms of interaction are as yet undefined. One possiblity suggested by studies in HBV transgenic mice is that chronic liver injury alters the expression of carcinogen metabolizing enzymes, thus modulating the level of binding of aflatoxin to DNA. Primary prevention of HCC in high incidence areas of the world should primarily be focused on provision of the safe, effective vaccine against HBV. However, measures to reduce the high levels of aflatoxin exposure, where chronic HBV infection is currently epidemic, would also significantly contribute to reducing HCC incidence. In Guinea-Conakry, West Africa, surveys of HBV infection and aflatoxin exposure have established baseline data for the implementation of a community-based intervention study. This study will evaluate the effectiveness of improving the post-harvest processing and storage of the groundnut crop, a major source of aflatoxins, using aflatoxin-albumin adducts as the outcome measurement. (C) 2002 Blackwell Publishing Asia Pty Ltd.