title: Scoring system development for prediction of extravesical bladder cancer.
abstract: OBJECTIVE
  Staging of bladder cancer is crucial for optimal management of the disease. However, clinical staging is not perfectly accurate. The aim of this study was to derive a simple scoring system in prediction of pathological advanced muscle-invasive bladder cancer (MIBC).
  
  
  METHODS
  Logistic regression and bootstrap methods were used to create an integer score for estimating the risk in prediction of pathological advanced MIBC using precystectomy clinicopathological data: demographic, initial transurethral resection (TUR) [grade, stage, multiplicity of tumors, lymphovascular invasion (LVI)], hydronephrosis, abdominal and pelvic CT radiography (size of the tumor, tumor base width), and pathological stage after radical cystectomy (RC). Advanced MIBC in surgical specimen was defined as pT3-4 tumor. Receiving operating characteristic (ROC) curve quantified the area under curve (AUC) as predictive accuracy. Clinical usefulness was assessed by using decision curve analysis.
  
  
  RESULTS
  This single-center retrospective study included 233 adult patients with BC undergoing RC at the Military Medical Academy, Belgrade. Organ confined disease was observed in 101 (43.3%) patients, and 132 (56.7%) had advanced MIBC. In multivariable analysis, 3 risk factors most strongly associated with advanced MIBC: grade of initial TUR [odds ratio (OR) = 4.7], LVI (OR = 2), and hydronephrosis (OR = 3.9). The resultant total possible score ranged from 0 to 15, with the cut-off value of > 8 points, the AUC was 0.795, showing good discriminatory ability. The model showed excellent calibration. Decision curve analysis showed a net benefit across all threshold probabilities and clinical usefulness of the model.
  
  
  CONCLUSIONS
  We developed a unique scoring system which could assist in predicting advanced MIBC in patients before RC. The scoring system showed good performance characteristics and introducing of such a tool into daily clinical decision-making may lead to more appropriate integration of perioperative chemotherapy. Clinical value of this model needs to be further assessed in external validation cohorts.
authors.forename: Rade
authors.initials: R
authors.lastname: Prelević
authors.forename: Miroslav M
authors.initials: MM
authors.lastname: Stojadinović
authors.forename: Dejan
authors.initials: D
authors.lastname: Simić
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Spasić
authors.forename: Nikola
authors.initials: N
authors.lastname: Petrović
mesh_terms: D005163:Factor Analysis, Statistical; D006801:Humans; D016015:Logistic Models; D015233:Models, Statistical; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D001749:Urinary Bladder Neoplasms / Q000473:pathology*