Preventable risk factors for prostate cancer are poorly understood; sun exposure is a possible protective factor. The goal of this study was to investigate prostate cancer risk in outdoor workers, a population with high sun exposure.
Prostate cancer cases and controls from a large study (conducted between 1994 and 1997) were used for this analysis. A job exposure matrix (JEM) was used to assign solar ultraviolet radiation (UVR) at work as moderate (2 to <6 hours outside/day) or high (≥6 hours). Average daily satellite UV-B measures were linked to the latitude/longitude of the residences of each participant. Several other exposure metrics were also examined, including ever/never exposed and standard erythemal dose by years (SED×years). Logistic regression was used to evaluate the association between solar UVR exposure and the odds of prostate cancer.
A total of 1638 cases and 1697 controls were included. Men of Indian and Asian descent had reduced odds of prostate cancer (ORs 0.17 (0.08 to 0.35) and 0.25 (0.15 to 0.41), respectively) compared with Caucasian men, as did single men (OR 0.76 (0.58 to 0.98)) compared with married men. Overall, no statistically significant associations were observed between sun exposure and prostate cancer with 1 exception. In the satellite-enhanced JEM that considered exposure in high category jobs only, prostate cancer odds in the highest quartile of cumulative exposure was decreased compared with unexposed men (OR 0.68 (0.51 to 0.92)).
This study found limited evidence for an association with prostate cancer, with the exception of 1 statistically significant finding of a decreased risk among workers with the longest term and highest sun exposure.
Occupational and environmental medicine. 2016 Jul 27 [Epub ahead of print]
Cheryl E Peters, Paul A Demers, Sunil Kalia, Perry Hystad, Paul J Villeneuve, Anne-Marie Nicol, Nancy Kreiger, Mieke W Koehoorn
Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada., Occupational Cancer Research Centre, Toronto, Ontario, Canada., Dermatology & Skin Science, University of British Columbia, Vancouver, British Columbia, Canada., College of Public Health and Human Sciences, Oregon State University, Corvallis, Oregon, USA., Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada., Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada., Department of Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada., School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.