Causes of increased mortality from hepatocellular carcinoma in high incidence country: Taiwan experience

Since 1991, a rapid rise in mortality from hepatocellular carcinoma (HCC) has been observed in Taiwan in subjects aged >/=20 years. The aim of the present study was to assess whether poor survival or excess incident cases pertaining to a cohort effect or a time-period effect accounted for such a rise.

A total of 41 150 deaths and 51 201 incident HCC patients (International Classification of Diseases = 155.0) aged 20-79 years between 1985 and 1998 were studied. Trends in HCC mortality rates were divided into two groups: annual case-fatality rates and HCC incidence rates by age. Poisson regression was used to distinguish a cohort effect from a time-period effect on the incidence of HCC.

Subjects aged >50 years after 1991 had the greatest risk of death (relative risk [RR] = 11.3; 95% confidence interval [CI]: 11.0-11.7). Annual case-fatality rates declined from 1.6 in 1985 to 0.84 in 1998, whereas there was a remarkable increase in incidence, particularly from 1991 onward, in the >50-year-olds. It was found that subjects aged >50 years who were born before 1944 were the group most susceptible to HCC (RR = 9.3; 95%CI: 9.1-9.5).

Increased incidence, particularly in individuals over 50, rather than poor survival, accounts for the rapid rise in mortality from HCC.