Occupational exposure to solar ultraviolet B radiation and risk of prostate cancer in Danish men

Objectives: Former epidemiological studies have indicated that solar ultraviolet B radiation (UV) may reduce the risk of prostate cancer, however, the evidence is inconclusive. To contribute with evidence, the present study aimed to evaluate the association between occupational UV exposure and prostate cancer in Danish men. Methods: A total of 12,268 men diagnosed with primary prostate cancer before age 70 were identified via the Danish Cancer Registry. The Danish Civil Registration System was used to randomly select five male controls matched on year of birth, alive and free of prostate cancer at the time of diagnosis of the index case. Full individual-level employment history was retrieved from the Danish Supplementary Pension Fund Register and linked to a job exposure matrix to assess occupational UV exposure. Conditional logistic regression was used to estimate odds ratios (ORs) with corresponding 95 % confidence intervals. Results: We observed an inverse association between ever exposure to occupational UV and prostate cancer (OR=0.93, 95 % CI: 0.89-0.97). Longer duration of exposure (>= 20 years: OR=0.90, 95 % CI: 0.84-0.96) and highest cumulative exposure (OR=0.90, 95 % CI: 0.84-0.96) were both inversely associated with disease risk. Conclusions: The present study indicates a modest protective effect from occupational UV exposure on the risk of prostate cancer. This finding needs further attention in future large-scale studies.