title: External validation of postoperative nomograms for prediction of all-cause mortality, cancer-specific mortality, and recurrence in patients with urothelial carcinoma of the bladder.
abstract: BACKGROUND
  The Bladder Cancer Research Consortium (BCRC) created nomograms to predict all-cause mortality (ACM), cancer-specific mortality (CSM), and recurrence after radical cystectomy (RC) for urothelial carcinoma of the bladder (UCB).
  
  
  OBJECTIVE
  To perform a formal validation of the BCRC nomograms in a large multi-institutional patient cohort from Europe.
  
  
  METHODS
  Records of 2501 patients who underwent RC for UCB at eight European centers were reviewed. Complete information for external validation was available in 2404 patients for the ACM and CSM nomograms and in 2243 patients for the recurrence nomogram.
  
  
  METHODS
  For the purpose of external validation, model discrimination was measured using the receiver operating characteristics derived area under the curve. Calibration plots examined the relationship between predicted and observed probabilities at 2 yr, 5 yr, and 8 yr. Decision curve analyses were applied to assess the net benefit derived from the three models.
  
  
  CONCLUSIONS
  The discrimination accuracies of the BCRC nomograms for ACM and CSM at 2 yr, 5 yr, and 8 yr after RC were 71.0%, 69.1%, and 68.2%, and 74.9%, 73.1%, and 72.4%, respectively. The accuracy of discrimination for the recurrence nomogram at the same time points was 76.5%, 75.3%, and 74.9%, respectively. Calibration plots revealed slight underestimations from ideal predictions. Decision curve analyses showed an increased net benefit for the use of the BCRC nomograms in this cohort. Limitations include the retrospective study design, potential surgeon bias, and lack of a central pathologic review.
  
  
  CONCLUSIONS
  The ACM, CSM, and recurrence nomograms showed acceptable predictive accuracies and could thus be adopted into clinical practice in UCB patients treated in Europe.
authors.affiliation: Department of Urology, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Nuhn
authors.forename: Matthias
authors.initials: M
authors.lastname: May
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Fritsche
authors.forename: Sabine
authors.initials: S
authors.lastname: Brookman-May
authors.forename: Alexander
authors.initials: A
authors.lastname: Buchner
authors.forename: Christian
authors.initials: C
authors.lastname: Bolenz
authors.forename: Rudolf
authors.initials: R
authors.lastname: Moritz
authors.forename: Edwin
authors.initials: E
authors.lastname: Herrmann
authors.forename: Maximilian
authors.initials: M
authors.lastname: Burger
authors.forename: Derya
authors.initials: D
authors.lastname: Tilki
authors.forename: Lutz
authors.initials: L
authors.lastname: Trojan
authors.forename: Paul
authors.initials: P
authors.lastname: Perrotte
authors.forename: Axel
authors.initials: A
authors.lastname: Haferkamp
authors.forename: Markus
authors.initials: M
authors.lastname: Hohenfellner
authors.forename: Wolf F
authors.initials: WF
authors.lastname: Wieland
authors.forename: Stefan C
authors.initials: SC
authors.lastname: Müller
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Bastian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality* / Q000556:secondary / Q000601:surgery*; D002423:Cause of Death; D015653:Cystectomy / Q000009:adverse effects / Q000401:mortality*; D016002:Discriminant Analysis; D005060:Europe; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D049451:Nomograms; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D019459:Urothelium / Q000473:pathology / Q000601:surgery*