[Hepatocellular carcinoma: a preventable cancer].

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and a public health concern in many developing countries. The main risk factor is the chronic carriage state of the hepatitis B virus which is found in about 20% of the adult population in many African and Asian countries. Other important risk factors are HCV infection, aflatoxin exposure and alcohol consumption. The Gambia Hepatitis Intervention Study was launched in 1986 with the aim of evaluating the efficacy of the hepatitis B vaccination, given in early infancy, in preventing HBV infection, its chronic carriage status, and later, HCC. For this purpose, a randomised vaccine trial was designed and carried out. Over a period of four years a total of 124.577 children were recruited, one half received the usual EPI vaccines (BCG, DTP, OPV, measles, yellow fever) and the other half the hepatitis B vaccine in addition to the EPI ones. Hepatitis B vaccination has been successfully integrated into the "Expanded Programme of Immunization" in The Gambia, since every new born baby can receive this vaccination in addition to the EPI vaccine. The first mid point evaluation showed that in four-year-old children, hepatitis B vaccine efficacy was 84% in preventing infection and 94% in preventing chronic carriage status of HBV. Other mid point evaluations are still ongoing. A nationwide Cancer Registry was set up to detect HCC cases in the cohort under study. Follow-up through the Cancer Registry is planned for the next 30 years.