Hepatitis B vaccination and hepatocellular carcinoma in Taiwan

Objective. In 1984, Taiwan started a large-scale hepatitis B vaccination program, enabling us to test the hypothesis that prevention of hepatitis B virus infection eventually decreases the incidence of hepatocellular carcinoma. Methods. Groups aged 0 to 9 years and 10 to 100 years in each calendar year were defined as the study group and the reference group, respectively. The percentage of children vaccinated in the study group increased during recent years. The study group and the reference group were divided into 5-year age strata (0 to 4, 5 to 9,..., 80 to 84, and 85 and over). Poisson regression was used to estimate age- and gender-adjusted liver carcinoma mortality rate ratios for 1974 through 1993, relative to 1974. Results. The adjusted mortality rate ratios of liver carcinoma in the study group decreased significantly for 1992 and 1993, whereas in the reference group it did not show the same result. A significantly declining trend of liver carcinoma mortality rate ratios was observed in the study group after 1984, whereas the same trend was not found in the reference group. Conclusions. Our results support the hypothesis that hepatitis B vaccination can decrease the incidence of hepatocellular carcinoma.