Descriptive epidemiology of pancreatic cancer in Japan.

This paper aimed to explore descriptive epidemiological features of pancreatic cancer in Japan, by examining secular trends in mortality (1950-1995) and incidence rates (1975-1991), and also to discuss background factors possibly ascribable to the recent variation in mortality and incidence rates. The age-adjusted mortality rate (adjusted by the 1985 model population) has increased by approximately 9-fold in both males (from 1.4 to 12.5 per 100,000 population) and females (from 0.8 to 6.8 per 100,000 population) between 1950 and 1995. But it began to level off in both sexes since 1985. The age-adjusted incidence rate has remained plateau in both sexes, but likely showed a downward trend since 1988 in females. The older age groups showed the most steep increasing gradient in both age-specific mortality and incidence rates in both sexes, whereas a little or no apparent increase was observed in young age groups. Diagnostic improvement and increased cigarette consumption were believed to be the two major factors contributing to the increased mortality and incidence rates in Japan, but further epidemiological studies will be required to clarify possible background factors for the recent levelling-off of the mortality and incidence rates.