title: External validation of the Prostate Cancer Prevention Trial risk calculator in a screened population.
abstract: OBJECTIVE
  To evaluate the recently developed Prostate Cancer Prevention Trial (PCPT) prostate cancer risk calculator in the San Antonio Center of Biomarkers of Risk for Prostate Cancer (SABOR) cohort of the Early Detection Research Network, a younger and more ethnically diverse population than that in the PCPT.
  
  
  METHODS
  From 3488 SABOR participants, we identified 446 who had undergone prostate biopsy and had undergone prostate-specific antigen measurement and digital rectal examination before biopsy. Most biopsies were performed for abnormal digital rectal examination findings, a prostate-specific antigen level of more than 2.5 ng/mL, or elevated risk because of a first-degree relative with prostate cancer. We evaluated the operating characteristics of the PCPT calculator for detecting prostate cancer in this cohort of SABOR participants. Of the 446 men in this cohort, 24% were younger than 55 years of age.
  
  
  RESULTS
  Of the 446 men who had undergone biopsy, 148 (33.2%) had prostate cancer. The observed SABOR prostate cancer rates increased with increasing PCPT risk: 15.7%, 39.0%, 48.8%, and 100.0% for a PCPT risk calculator value of less than 25%, 25% to 50%, 50% to 75%, and greater than 75%, respectively. The PCPT risk calculator had an area under the receiver operating characteristic curve of 65.5% (95% confidence interval 60.2% to 70.8%, P < 0.0001), was greater in African-American men (area under curve of 80.0%, 95% confidence interval 67.8% to 92.2%) than in other races (P = 0.02), and was not different in Hispanic men (P > 0.05).
  
  
  CONCLUSIONS
  The results of our study have shown that the PCPT risk calculator, available from the Internet and incorporating the current best panel of risk factors, is valid in other, more diverse, populations.
authors.affiliation: Department of Urology, University of Texas Health Science Center, San Antonio, Texas 78229, USA. parekhd@uthscsa.edu
authors.forename: Dipen J
authors.initials: DJ
authors.lastname: Parekh
authors.forename: Donna Pauler
authors.initials: DP
authors.lastname: Ankerst
authors.forename: Betsy A
authors.initials: BA
authors.lastname: Higgins
authors.forename: Javier
authors.initials: J
authors.lastname: Hernandez
authors.forename: Edith
authors.initials: E
authors.lastname: Canby-Hagino
authors.forename: Timothy
authors.initials: T
authors.lastname: Brand
authors.forename: Dean A
authors.initials: DA
authors.lastname: Troyer
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Leach
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
mesh_terms: D000368:Aged; D001706:Biopsy; D002986:Clinical Trials as Topic / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000517:prevention & control*; D018570:Risk Assessment / Q000379:methods*
chemical_list: D017430:Prostate-Specific Antigen