Age-period-cohort analysis of hepatocellular carcinoma mortality in Taiwan, 1976-2005

Abstract

Purpose: Hepatocellular carcinoma (HCC) is one of the most common malignant primary liver tumors worldwide. A previous study showed a decline in pediatric HCC in Taiwan after the universal vaccination program was initiated in 1984. We investigated whether the recent change in HCC mortality in Taiwan represented a short-term fluctuation or an emerging long-term decline trend.

Methods: An age-period-cohort analysis was conducted to show HCC mortality trends between 1976 and 2005. A total of 121,643 HCC mortality cases (92,926 males and 28,717 females) of individuals older than 40 years of age was used in the analyses.

Results: Results indicate an increasing secular trend in HCC mortality over the last three decades in people aged 60 years and above. In the age group of >85 years old, the mortality rate for males and females was 7.47 (95% confidence interval [95% CI]: 6.24-8.94) and 25.0 (95% CI: 15.5-40.2) times greater than in the youngest age group (40-44), respectively. The relative risk of dying from HCC in the period 2001-2005 was 1.36 (95% CI: 1.23-1.50) for males compared to the 1976-1980 time period, and 1.42 (95% CI: 1.17-1.72) for females compared to the 1986-1990 time period. A strong birth-cohort effect was also found. Individuals born around 1936 had the highest risk of dying from HCC.

Conclusion: These findings imply that important determinants of HCC may occur early in life, with their effects only becoming apparent much later.