Larry Clark's legacy: randomized controlled, selenium-based prostate cancer chemoprevention trials

Several important clinical trials under way at the Arizona Cancer Center seek to build on the results of Clark's 1996 study of selenium and decreased risk of prostate cancer. Those results, an unanticipated end point of a clinical trial, suggest that selenium has significant preventive power. The studies under way involve continued follow-up of the study cohort that generated the 1996 results and trials of selenium among men with negative biopsies, men with high-grade prostatic intraepithelial neoplasia, men with prostate cancer treated with selenium before prostatectomy, and men with prostate cancer who have chosen watchful waiting rather than active intervention. These studies promise important opportunities to validate Clark's original results.