Hepatocellular carcinoma in Taiwan

Hepatocellular carcinoma (HCC) is common in Taiwan. The age-adjusted incidence rates have been increasing, from approximately 15/100000 in the 1980s to approximately 30/100 000 recently. The main causes are chronic hepatitis B and C infections, with >90% of patients positive for hepatitis B surface antigen (HBsAg) or antibody to hepatitis C virus (antiHCV). Before 1990, approximately 80% of patients with HCC were positive for HBsAg. The infection is mainly from perinatal mother-to-infant transmission. HCV is the second important cause, accounting for approximately 70% of HBsAg negative patients. Overall, 5-10% patients have infections of both viruses. In HBsAg negative-anti-HCV negative patients, polymerase chain reaction assay still reveals the key role of HBV. Epidemiologic studies also reveal the important role of HBV. In a nested case-control study, cumulative incidence of HCC was 10% after nine years of follow-up in hepatitis B e-antigen (HBeAg) positive carriers, with a relative risk of 60.2 compared to 9.6 in HBeAg negative carriers. The role of high viral load was confirmed when another community-based prospective study of 3644 HBsAg carriers stratified by serum hepatitis B virus (HBV) DNA levels correlated well with the occurrence of HCC, especially in carriers with levels >10(5) copies/mL. Genotype C infection contributed more to hepatocarcinogen-esis than genotype B. Although HBV is dominant in causing HCC, in the last two decades the relative importance of HCV has changed. The proportion of anti-HCV positive cases has increased. In some areas of southern Taiwan where HCV infection is rampant, HCV-associated HCC have surpassed HBV-associated cases. To control hepatitis B, a mass neonatal vaccination program against hepatitis B was launched in 1984. The HBsAg carrier rate decreased from the historical 15-20% to < 1% after vaccination. Most importantly, annual incidence of childhood HCC has decreased from 0.67 to 0. 19/ 100 000 children. To control hepatitis C, besides interrupting the transmission routes and screening blood donors with antiHCV, treatment with interferon and ribavirin was implemented on a national basis in 2003. Through these efforts, virally-induced HCC will be controlled in 20-30 years, and a decrease of approximately 85% is anticipated by 2040. Then, HCC will not be commonly seen in Taiwanese people, and the major cause of HCC will be non-viral factors that lead to cirrhosis, such as non-alcoholic steato hepatitis.