title: External validation of a Brazilian predictive nomogram for pathologic outcomes following radical prostatectomy in tertiary teaching institutions: the USP nomograms.
abstract: OBJECTIVE
  (a) To externally validate the Crippa and colleagues' nomograms combining PSA, percentage of positive biopsy cores (PPBC) and biopsy Gleason score to predict organ-confined disease (OCD) in a contemporary sample of patients treated at a tertiary teaching institution. (b) To adjust such variables, resulting in predictive nomograms for OCD and seminal vesicle invasion (SVI): the USP nomograms.
  
  
  METHODS
  The accuracy of Crippa and colleagues' nomograms for OCD prediction was examined in 1002 men submitted to radical prostatectomy between 2005 and 2010 at the University of São Paulo (USP). ROC-derived area under the curve (AUC) and Brier scores were used to assess the discriminant properties of nomograms for OCD. Nomograms performance was explored graphically with LOESS smoothing plots. Furthermore, univariate analysis and logistic regression models targeted OCD and SVI. Variables consisted of PSA, PPBC, biopsy Gleason score and clinical stage. The resulted predictive nomograms for OCD and SVI were internally validated with bootstrapping and the same abovementioned procedures.
  
  
  RESULTS
  Crippa and colleagues' nomograms for OCD showed ROC AUC = 0.68 (CI: 0.65-0.70), Brier score = 0.17 and overestimation in LOESS plots. USP nomograms for OCDand SVI showed ROC AUC of 0.73 (CI: 0.70-0.76) and 0.77 (CI: 0.73-0.79), respectively, and Brier scores of 0.16 and 0.08, respectively. The LOESS plots showed excellent calibration for OCD and underestimation for SVI.
  
  
  CONCLUSIONS
  Crippa and colleagues' nomograms showed moderate discrimination and considerable OCD overestimation. USP nomograms showed good discrimination for OCD and SVI, as well as excellent calibration for OCD and SVI underestimation.
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Aguinel José
authors.initials: AJ
authors.lastname: Bastian
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Marcos F
authors.initials: MF
authors.lastname: Dall'Oglio
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Crippa
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Getúlio Rodrigues de
authors.initials: GR
authors.lastname: Oliveira Filho
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Luís Felipe
authors.initials: LF
authors.lastname: Piovesan
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Ricardo Kupka da
authors.initials: RK
authors.lastname: Silva
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Katia R M
authors.initials: KR
authors.lastname: Leite
authors.affiliation: Urology Division, University of São Paulo Medical School, São Paulo, Brazil and Cancer Institute of Sao Paulo, São Paulo, Brazil.
authors.forename: Miguel
authors.initials: M
authors.lastname: Srougi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001938:Brazil; D002138:Calibration; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049451:Nomograms; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D012016:Reference Values; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012669:Seminal Vesicles / Q000473:pathology*; D012680:Sensitivity and Specificity; D062606:Tertiary Care Centers
chemical_list: D017430:Prostate-Specific Antigen