Etiology of hepatocellular carcinoma in Africa.

The important factors in the causation of hepatocellular carcinoma (HCC) in Africa include hepatitis B virus (HBV), aflatoxin and possibly malnutrition. The evidence in support of an association of HBV with HCC is mainly epidemiological and includes: (a) the similarity between the geographical distribution of chronic carriers of hepatitis B surface antigen (HBsAg) and that of HCC; (b) the increased prevalence of HBV markers in the serum of patients with HCC when compared with the general population; and (c) the observation that HBV infection precedes the general development of the tumour and that HBV infection increases the risk of HCC over 200-fold. Laboratory evidence has shown that HBV DNA is integrated in the host tissue in patients with HCC. A vaccination programme in Senegal showed that hepatitis B vaccine reduced HBV infection and it is hoped that it will eventually lead to a reduction in HCC. Studies in East Africa have shown a correlation between aflatoxin contamination and the incidence of HCC. The possible roles of malnutrition and/or alcohol are discussed.