Hepatocellular carcinoma in the Asia pacific region

Primary liver cancer, particularly hepatocellular carcinoma (HCC) remains a significant disease worldwide. It is among the top three causes of cancer death in the Asia Pacific region because of the high prevalence of its main etiological agents, chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. In this region, the incidence of HCC has been static over recent decades. Older age is a major risk factor; the incidence increasing sharply after age 40 years. There is a male predilection, with male to female ratio of 3:1, except in elderly Japanese with equal sex incidence or female predominance. In most Asia-Pacific countries, chronic HBV infection accounts for 75-80% of cases; Japan, Singapore and Australia/New Zealand are exceptions because of higher prevalence of HCV infection. In spite of advances in surgery, liver transplantation and newer pharmaco/biological therapies, the survival rate has improved only slightly over recent decades, and this could be attributable to earlier diagnosis ('lead-time bias'). The majority of patients present with advanced diseases, hence reducing the chance of curative treatment. The importance of HCC may decrease in two to three decades when the prevalence of chronic HBV infection decreases as a result of the universal HBV vaccination programs implemented in late 1980s in most Asia-Pacific countries, and because of reduced incidence of medical transmission of HCV. However, transmission of HCV by injection drug use, and rising prevalence of obesity and diabetes, both independent risk factors for HCC, may partly offset this decline.