Epidemiology and Clinical Presentation of Hepatocellular Carcinoma Hepatocellular carcinomas are one of the main complications of liver cirrhosis and a serious health problem worldwide. The incidence of hepatocellular carcinoma varies between different countries, depending on the prevalence of several risk factors such as chronic viral hepatitis B or C, contamination of food with aflatoxin, and alcohol abuse. The incidence of hepatocellular carcinoma is low in developed Western countries, but in some areas of Africa or China, hepatocellular carcinoma is the major cause of tumor-related death. The incidence of hepatocellular carcinoma is rising in all developed Western countries, which can be explained, at least in part, by the increasing prevalence of hepatitis C virus infection. The development of hepatocellular carcinoma in patients with chronic hepatitis C infection needs approximately 20–30 years. Consequently, it has been predicted that the burden of hepatocellular carcinoma in developed Western countries will increase in the next 2–3 decades, possibly to equal rates as currently experienced in Japan. Although liver cirrhosis per se appears to be the primary risk factor for hepatocellular carcinoma, hepatocarcinogenesis strongly depends also on the causes of liver cirrhosis. Depending on the underlying disease, patients with high risk (chronic viral hepatitis B or C, hemochromatosis, tyrosinemia) and those with low risk (morbus Wilson, primary biliary cirrhosis, primary sclerosing cholangitis) for the development of hepatocellular carcinoma can be identified. The prognosis of patients with hepatocellular carcinoma is independent of the underlying disease, but depends on the liver function and the tumor stage.