Primary and secondary prevention of liver cancer caused by HBV.

Primary cancer of the liver (hepatocellular carcinoma, HCC) is one of the most common cancers worldwide; HBV is the major cause of HCC. A vaccine that protects against HBV infection was invented in 1969 and is now one of the most commonly used vaccines. National vaccination programs have dramatically reduced the prevalence of HBV infection and carriers, with a concomitant decrease in the incidence of HCC in the vaccine-impacted populations. HBV vaccine is the first widely used cancer prevention vaccine; a second that protects against papilloma virus and cancer of the cervix has recently been introduced. Appropriate treatment of HBV carriers with antivirals can reduce the titers of HBV in their blood and thereby greatly reduce the risk of HCC and chronic liver disease. Further data are required to establish criterion for treatment to enable protocols for medical and prevention programs. There are other viral caused cancers and an understanding of their pathogenesis is an important future direction for research to reduce the human burden of cancer.