Advanced Prostate Cancer Risk in Relation to Toenail Selenium Levels

BACKGROUND: Selenium may prevent advanced prostate cancer (PCa), but on this topic were conducted in populations with moderate to high status. We investigated the association of toenail selenium, reflecting selenium exposure, and advanced PCa risk in a population from the where low selenium status is widespread. METHODS: The analysis was the prospective Netherlands Cohort Study, which included 58 279 men aged years at baseline in 1986. All cohort members completed a baseline and approximately 79% of participants provided toenail clippings, which for toenail selenium measurements using instrumental neutron activation Incident advanced PCa case subjects from the entire cohort were 17.3 years of follow-up. The study employed a case-cohort design for random subcohort was sampled at baseline. Hazard ratios and 95% intervals (CIs) were estimated using Cox proportional hazards regression All tests were two-sided. RESULTS: Complete toenail selenium data were for 898 advanced (International Union Against Cancer stage III/IV) PCa subjects and 1176 subcohort members. The average toenail selenium of subcohort members was 0.550 microg/g. Toenail selenium was associated reduced risk of advanced PCa; adjusted hazard ratio for the highest vs quintile was 0.37 (95% CI = 0.27 to 0.51; P trend < .001). For stage IV in the highest vs lowest quintile of toenail selenium had an adjusted ratio of 0.30 (95% CI = 0.21 to 0.45; P trend < .001). CONCLUSIONS: selenium was associated with a substantial decrease in risk of advanced