Interpreting trends of pancreatic cancer incidence and mortality: a nation-wide study in Sweden (1960–2003)

Abstract

We investigated temporal trends of pancreatic cancer in Sweden measured with suboptimal sensitivity and specificity both by incidence and by mortality rates. 46,257 incident cases of pancreatic cancer from the Swedish Cancer Register and 53,686 mortality cases from the Causes of Death Register during 1960-2003 were used to calculate age-standardized incidence or mortality rates. We further assessed the impact of changes in diagnostic practice on the observed trends, and investigated the effect of calendar period and birth cohort by age-period-cohort modeling. Overall, the pattern of trends in age-adjusted rates of pancreatic cancer was similar irrespective of whether incidence or mortality was used. The age-adjusted rates of pancreatic cancer increased during the first decade and then peaked for both sexes (the male peak occurred in the early 1970s and the female peak in the 1980s) followed by a steady decline in both groups. An age-period model provided the best fit to the observed trends among patients diagnosed at ages 35-74 in both sexes. The close agreement between the incidence and mortality and the gender disparity suggest a true decline in pancreatic cancer incidence in recent years in Sweden, and gender-specific trends in exposure to environmental risk factors.