Current status of liver diseases in Korea: hepatocellular carcinoma.

Primary liver cancer, most of which is hepatocellular carcinoma (HCC), is the third common leading cancer in Korea. During the last two decades, the incidence rate of primary liver cancer has shown a modest decrease, but its mortality rate has slightly increased. The incidence of HCC, according to age, peaks in the late sixth decade in men and in the early seventh decade in women. Hepatitis B virus (HBV) is the most important risk factor, which represents approximately 70% of all HCC, and hepatitis C virus (HCV) and alcohol are the next in order of major risk factors for the development of HCC in Korea. HBV-associated HCC occurs 10 years earlier than HCV-associated HCC due to a more prolonged exposure to HBV, which is vertically transmitted almost from HBsAg-positive mother in HBV-endemic area. National Cancer Control Institute, which was reorganized in 2005, is now working for several national projects such as National Cancer Registration Program, National R&D Program for Cancer Control and National Cancer Screening Program. International collaboration for the clinico-epidemiologic research would be needed to provide the specific measures for managing HCC in diverse etiologic situations. Finally, the mechanisms of hepatitis virus-associated hepatocellular carcinogenesis might be clarified to provide insights into the advanced therapeutic and preventive approaches for HCC in Korea, where the majority of HCC originate from chronic HBV and HCV infections.