Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC): Molecular mechanisms and novel paradigms

Chronic hepatitis B (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). Most HCCs complicate the evolution of an active or inactive cirrhosis. However, some tumors occur on livers with minimal histological changes; the prevalence of such cases varies from one geographical region to the other, being much higher in the Southern half of Africa (around 40% of HCCs) than in Asia, America and Europe, where at least 90% of HCCs are associated in the cirrhosis. This heterogeneity is probably a reflection of different environmental and genetic factors. This review will summarise the current knowledge on the mechanisms involved in HBV-related liver carcinogenesis. It will show in particular how viruses can be viewed as tools to discover and dissect new cellular pathways involved in cancer development and emphasize the potential synergistic effects between HBV and hepatitis C virus (HCV), as well as between viral infections and other environmental factors, such as alcohol.

RésuméUne infection chronique par le virus de l’hépatite B (VHB) est un facteur de risque majeur pour le développement des cancers primitifs du foie. La tumeur se développe le plus souvent sur un foie cirrhotique et l’inflammation chronique ainsi que la fibrose hépatique sont des éléments essentiels de la carcinogénèse hépatique. Le VHB intervient également directement à certaines étapes de la carcinogénèse. Cette revue résume l’état des connaissances sur ces sujets et montre comment l’épidémiologie des cancers du foie dus au VHB doit être analysée en tenant compte de l’ensemble des marqueurs, en particulier moléculaires, disponibles.