Age-period-cohort analysis of pancreatic cancer mortality in Taiwan, 1971-1986.

Interest has recently emerged about the increasing trend of pancreatic cancer mortality in Taiwan, particularly in the elderly. The mortality data of pancreatic cancer over the period 1971-1986 for males and females aged 40-84 in Taiwan were analysed using a log-linear Poisson model to examine the effects of age, calendar period of death, and birth cohort. This age-period-cohort model provides a summary guide for the reading and interpretation of cancer mortality trends. Age is the strongest factor in predicting pancreatic cancer mortality according to the models; the oldest age group 80-84 years old has 14.5 times the risk of the youngest age group 40-44. The cohort effect is also of particular interest because the generation at greatest risk for pancreatic cancer in both sexes, is the one born between 1917 and 1926, and a declining trend is observed thereafter for more recent cohorts. Parameters of the period factor show no observable trend before 1975, followed by a significantly increasing risk in the subsequent time period. However, the drop of pancreatic cancer mortality over all age groups between 1985-86 is puzzling and a further study to monitor the secular trends in the following years is warranted.