O22-2 Outdoor workers’ reduced risk of prostate cancer

Objectives Prostate cancer is the second most common cancer in Canadian men, but preventable risk factors are poorly understood. Vitamin D has been hypothesised to be a protective agent, so the goal of this study was to investigate the potentially reduced risk of prostate cancer in outdoor workers, a population at risk of high exposure to the sun. Methods Prostate cancer cases and controls in a large Canadian population-based case-control study (carried out between 1994 and 1997) were used for this analysis. A job exposure matrix (SUNJEM) was used to assign exposure in 2 categories: moderate (2 ≤ 6 hours outside/day) or high (≥6). Satellite UV-B measures were linked to the latitude/longitude of each residence during the working life. Several exposure metrics were examined including a cumulative measure of standard erythemal dose – years (SED-years). Logistic regression was used to evaluate the association between the various measures of occupational solar UVR exposure and prostate cancer. Results A total of 3,335 men were included (1638 cases, 1697 controls). 737 cases (45%) and 713 controls (42%) were ever exposed to solar UVR at work. In the satellite-enhanced SUNJEM that only considered exposure in high category jobs, the risk of prostate cancer was decreased compared to unexposed men, and the highest exposure group had an OR for prostate cancer of 0.68 (95% CI: 0.51–0.92). Conclusion This study found that long-term outdoor workers may have a decreased risk of prostate cancer.