Viral Hepatitis and Liver Cancer in Korea: an Epidemiological Perspective

Abstract

In the past, hepatitis B virus (HBV) infection was endemic in the general Korean population. The associationof HBV infection with the occurrence of liver cancer has been well demonstrated in several epidemiologic studies.While the mortality rates of liver cancer in Korea have decreased steadily over the last decade, the presenceof hepatitis B surface antigen (HBsAg) in mothers remains high at 3-4%, and 25.5% of these HBsAg positivemothers are positive for hepatitis B e antigen (HBeAg). HBV infection caused almost a quarter of hepatocellularcarcinoma (HCC) cases and one-third of deaths from HCC. These aspects of HBV infection prompted the Koreangovernment to create a vaccination program against HBV in the early 1980s. In 1995, the Communicable DiseasePrevention Act (CDPA) was reformed, and the government increased the number of HBV vaccines in the NationalImmunization Program (NIP), driving the vaccination rate up to 95%. In 2000, the National Health InsuranceAct (NHIA) was enacted, which provided increased resources for the prevention of perinatal HBV infection.Then in 2002, the Korean government, in conjunction with the Korean Medical Association (KMA), launchedan HBV perinatal transmission prevention program. The prevalence of HBsAg in children had been high (4-5%)in the early 1980s, but had dropped to below 1% in 1995, and finally reached 0.2% in 2006 after the NIP hadbeen implemented. After the success of the NIP, Korea finally obtained its first certification of achievement fromthe Western Pacific Regional Office of the World Health Organization (WPRO-WHO) for reaching its goal forHBV control. An age-period-cohort analysis showed a significant reduction in the liver cancer mortality ratein children and adolescents after the NIP had been implemented. In addition to its vaccination efforts, Korealaunched the National Cancer Screening Program (NCSP) for 5 leading sites of cancer, including the liver, in1999. As a consequence of this program, the 5-year liver cancer survival rate increased from 13.2% (1996-2000)to 23.3% (2003-2008). The development of both the primary and secondary prevention for liver cancer includingHBV immunization and cancer screening has been of critical importance.