title: Prostate Cancer Prevention Trial risk calculator 2.0 for the prediction of low- vs high-grade prostate cancer.
abstract: OBJECTIVE
  To modify the Prostate Cancer Prevention Trial risk calculator (PCPTRC) to predict low- vs high-grade (Gleason grade≥7) prostate cancer and incorporate percent free-prostate-specific antigen (PSA).
  
  
  METHODS
  Data from 6664 Prostate Cancer Prevention Trial placebo arm biopsies (5826 individuals), where prostate-specific antigen and digital rectal examination results were available within 1 year before the biopsy and PSA was ≤10 ng/mL, were used to develop a nominal logistic regression model to predict the risk of no vs low-grade (Gleason grade<7) vs high-grade cancer (Gleason grade≥7). Percent free-PSA was incorporated into the model based on likelihood ratio analysis of a San Antonio Biomarkers of Risk cohort. Models were externally validated on 10 Prostate Biopsy Collaborative Group cohorts and 1 Early Detection Research Network reference set.
  
  
  RESULTS
  Of all the Prostate Cancer Prevention Trial biopsies, 5468 (82.1%) were negative for prostate cancer, 942 (14.1%) detected low-grade, and 254 (3.8%) detected high-grade disease. Significant predictors were (log base 2) PSA (odds ratio for low-grade vs no cancer, 1.29*; high-grade vs no cancer, 2.02*; high-grade vs low-grade cancer, 1.57*), digital rectal examination (0.96, 1.49*, 1.55*, respectively), age (1.02*, 1.05*, 1.03*, respectively), African American race (1.13, 2.83*, 2.51*, respectively), prior biopsy (0.63*, 0.81, 1.27, respectively), and family history (1.31*, 1.25, 0.95, respectively), where * indicates P value<.05. The new PCPTRC 2.0 either with or without percent free-PSA (also significant by the likelihood ratio method) validated well externally.
  
  
  CONCLUSIONS
  By differentiating the risk of low- vs high-grade disease on biopsy, PCPTRC 2.0 better enables physician-patient counseling concerning whether to proceed to biopsy.
authors.affiliation: Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, TX; Department of Epidemiology and Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, TX; Department of Mathematics, Technical University Munich, Garching, Germany. Electronic address: ankerst@uthscsa.edu.
authors.forename: Donna P
authors.initials: DP
authors.lastname: Ankerst
authors.affiliation: Department of Mathematics, Technical University Munich, Garching, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Hoefler
authors.affiliation: Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bock
authors.affiliation: Department of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA.
authors.forename: Phyllis J
authors.initials: PJ
authors.lastname: Goodman
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Andrew
authors.initials: A
authors.lastname: Vickers
authors.affiliation: Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Javier
authors.initials: J
authors.lastname: Hernandez
authors.affiliation: Department of Oncology, Johns Hopkins Medical Institutions, Baltimore, MD.
authors.forename: Lori J
authors.initials: LJ
authors.lastname: Sokoll
authors.affiliation: Department of Urology, Emory University School of Medicine, Atlanta, GA.
authors.forename: Martin G
authors.initials: MG
authors.lastname: Sanda
authors.affiliation: Department of Urology, University of Michigan School of Medicine, Ann Arbor, MI.
authors.forename: John T
authors.initials: JT
authors.lastname: Wei
authors.affiliation: Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, TX; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Leach
authors.affiliation: Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D051517:Digital Rectal Examination / Q000379:methods; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D016013:Likelihood Functions; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology*; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011322:Primary Prevention / Q000379:methods; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000517:prevention & control*; D015203:Reproducibility of Results; D018570:Risk Assessment
chemical_list: D017430:Prostate-Specific Antigen