title: Prostate cancer prevention: strategies for agent development.
abstract: OBJECTIVE
  This article provides an update of clinical research supported by the National Cancer Institute's Phase I/II prostate cancer chemoprevention agent development program.
  
  
  RESULTS
  Numerous clinical trials of pharmacologic interventions to delay, prevent or reverse carcinogenesis ('chemoprevention') with the ultimate goal of reducing cancer incidence have been conducted over the past decade. These trials range from relatively small, short-duration studies with biomarker endpoints to very large, long-term, general population trials with definitive cancer endpoints. Two large, population-based, Phase III prostate cancer prevention trials have shown a significant benefit for 5-α-reductase inhibitors. However, this class of agents was also associated with increased detection of high-grade prostate cancer. Another large, Phase III prostate cancer prevention trial showed no benefit for either selenium or vitamin E, given individually or in combination; in fact, a significant increase in prostate cancer was observed among men randomized to the vitamin E alone arm.
  
  
  CONCLUSIONS
  A number of early phase trials and three definitive Phase III trials have been conducted in the field of prostate cancer prevention over the past decade. Although a great deal has been learned from these studies, significant work remains to be done to fully realize the potential of chemoprevention in this disease.
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland 20892, USA. parnesh@mail.nih.gov
authors.forename: Howard L
authors.initials: HL
authors.lastname: Parnes
authors.forename: Margaret G
authors.initials: MG
authors.lastname: House
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Tangrea
mesh_terms: D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D002986:Clinical Trials as Topic; D055808:Drug Discovery; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000517:prevention & control*
chemical_list: D016588:Anticarcinogenic Agents