Associations between timing of exposure to ultraviolet radiation, T-stage and survival in prostate cancer.

Background: Exposure to ultraviolet radiation (UVR) has been inversely associated with prostate cancer risk. We determined if skin type and UVR exposure are linked with parameters of prostate cancer outcome.
Methods: We used a questionnaire to determine UVR exposure parameters and skin type in 553 men with prostate cancer and, using logistic regression and survival analysis, studied their association with T-stage, Gleason score, and survival after starting hormone manipulation therapy.
Results: UVR exposures 10, 20, and 30 years before diagnosis were inversely associated with T-stage. The odds ratio (OR) for UVR exposure 10 years before diagnosis was lowest (OR=0.69, 95% CI=0.56-0.86). ORs were lower in men with skin types I/II than III/IV. Skin types I/II were associated with longer survival after commencing hormone therapy (hazard ratio=0.62, 95% CI=0.40-0.95).
Conclusions: Our finding that UVR exposure is beneficial is compatible with accumulating data showing sunlight has a protective effect on disease phenotype.