Abstract 3431: Occupation and the risk of early- and later-onset prostate cancer in five Nordic countries
Authors: Barry Kathryn Hughes , Martinsen Jan Ivar , Alavanja Michael C.R. , Andreotti Gabriella , Blair Aaron , Hansen Johnni , Kjaerheim Kristina , Koutros Stella , Lynge Elsebeth , Sparen Par , Tryggvadottir Laufey , Weiderpass Elisabete , Berndt Sonja I. , Pukkala Eero 
Published: July 2016

Abstract
The etiology of prostate cancer remains largely unknown. Cases that occur late in life may have a different etiology than early-onset cases, and their inclusion in epidemiological studies may obscure associations with early-onset prostate cancer, which is often more aggressive and clinically relevant. We evaluated occupation in relation to the risk of prostate cancer separately for early-onset and later-onset disease in a large pooled study. We used census data to code occupations among census participants in five Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) from 1960-1990. We identified prostate cancer cases diagnosed from 1961-2005 by linkage to national cancer registries and calculated standardized incidence ratios (SIRs) by occupation separately for men aged 30-49 and those aged 50 or older. We also conducted separate analyses by period of cancer follow-up in two categories, 1961-1990 and 1991-2005, based on introduction of the prostate-specific antigen (PSA) screening test in the Nordic countries in 1990 or later. For early-onset prostate cancer, the highest SIRs were observed for public safety workers (e.g., firefighters) [SIR = 1.71, 95% confidence interval (CI): 1.23-2.31] and military personnel (SIR = 1.97, 95% CI: 1.31-2.85). These SIRs were significantly higher than those observed for later-onset disease (pheterogeneity = 0.005 and 0.002), with public safety workers and military personnel demonstrating SIRs of 1.10 (95% CI: 1.07-1.14) and 1.09 (95% CI: 1.05-1.13), respectively. Administrators (SIR = 1.41, 95% CI: 1.13-1.73) and technical workers (SIR = 1.18, 95% CI: 1.01-1.37) also demonstrated significantly increased risk for early-onset prostate cancer, although the SIRs did not significantly differ from those for later-onset disease (for administrators, SIR = 1.17, 95% CI: 1.15-1.19; pheterogeneity = 0.08, and for technical workers, SIR = 1.11, 95% CI: 1.09-1.12; pheterogeneity = 0.40). With the exception of public safety workers, for whom the SIR for early-onset prostate cancer was higher in the later period (for 1961-1990, SIR = 1.45, 95% CI: 0.79-2.43, and for 1991-2005, SIR = 1.87, 95% CI: 1.25-2.71), the observed associations with early-onset disease tended to be restricted to the earlier, pre-PSA period. Our results suggest that occupational exposures among public safety workers and military personnel may contribute to the risk of prostate cancer, particularly for early-onset disease.
Citation Format: Kathryn Hughes Barry, Jan Ivar Martinsen, Michael C.R. Alavanja, Gabriella Andreotti, Aaron Blair, Johnni Hansen, Kristina Kjaerheim, Stella Koutros, Elsebeth Lynge, Par Sparen, Laufey Tryggvadottir, Elisabete Weiderpass, Sonja I. Berndt, Eero Pukkala. Occupation and the risk of early- and later-onset prostate cancer in five Nordic countries. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3431.