Long-term trends in pancreatic cancer mortality in Spain (1952-2012)

Abstract

Background: Pancreatic cancer is acquiring increasing prominence as a cause of cancer death in the population. The purpose of this study was to analyze long-term pancreatic cancer mortality trends in Spain and evaluate the independent effects of age, death period and birth cohort on these trends.

Methods: Population and mortality data for the period 1952-2012 were obtained from the Spanish National Statistics Institute. Pancreatic cancer deaths were identified using the International Classification of Diseases ICD-6 to ICD-9 (157 code) and ICD-10 (C25 code). Age-specific and age-adjusted mortality rates were computed by sex, region and five-year period. Changes in pancreatic cancer mortality trends were evaluated using joinpoint regression analyses by sex and region. Age-period-cohort log-linear models were fitted separately for each sex, and segmented regression models were used to detect changes in period- and cohort-effect curvatures.

Results: In men, rates increased by 4.1% per annum from 1975 until the mid-1980s and by 1.1% thereafter. In women, there was an increase of 3.6% per annum until the late 1980s, and 1.4% per annum from 1987 to 2012. With reference to the cohort effects, there was an increase in mortality until the generations born in the 1950s in men and a subsequent decline detected by the change point in 1960. A similar trend was observed in women, but the change point occurred 10 years later than in men.

Conclusions: Pancreatic cancer mortality increased over the study period in both sexes and all regions. An important rise in rates -around 4% annually- was registered until the 1980s, and upward trends were more moderate subsequently. The differences among sexes in trends in younger generations may be linked to different past prevalence of exposure to some risk factors, particularly tobacco, which underwent an earlier decrease in men than in women.

Keywords: Age-period-cohort analysis; Change-points; Mortality; Pancreatic cancer; Spain; Time trends; Tobacco smoking.

Fig. 1

Pancreatic cancer mortality in Spain (2008–2012): AAMR per 100,000 person-years (1976 ESP) by Autonomous Community

Fig. 2

Pancreatic cancer mortality trends in Spain (1975–2012), by sex and Autonomous Community. Age-adjusted smoothed mortality rates per 100,000 person-years (1976 ESP)

Fig. 3

AAMR per 100,000 person-years for pancreatic cancer by birth cohort and sex, Spain (1952–2012)

Fig. 4

Cohort and period effects on pancreatic cancer mortality by sex, Spain (1952–2012). Cohort and period effects (thick lines), curvature (thin lines) and change points in the curvatures (vertical grey lines)