title: Risk prediction models of locoregional failure after radical cystectomy for urothelial carcinoma: external validation in a cohort of korean patients.
abstract: OBJECTIVE
  To evaluate the predictive accuracy and general applicability of the locoregional failure model in a different cohort of patients treated with radical cystectomy.
  
  
  METHODS
  A total of 398 patients were included in the analysis. Death and isolated distant metastasis were considered competing events, and patients without any events were censored at the time of last follow-up. The model included the 3 variables pT classification, the number of lymph nodes identified, and margin status, as follows: low risk (≤pT2), intermediate risk (≥pT3 with ≥10 nodes removed and negative margins), and high risk (≥pT3 with <10 nodes removed or positive margins).
  
  
  RESULTS
  The bootstrap-corrected concordance index of the model 5 years after radical cystectomy was 66.2%. When the risk stratification was applied to the validation cohort, the 5-year locoregional failure estimates were 8.3%, 21.2%, and 46.3% for the low-risk, intermediate-risk, and high-risk groups, respectively. The risk of locoregional failure differed significantly between the low-risk and intermediate-risk groups (subhazard ratio [SHR], 2.63; 95% confidence interval [CI], 1.35-5.11; P<.001) and between the low-risk and high-risk groups (SHR, 4.28; 95% CI, 2.17-8.45; P<.001). Although decision curves were appropriately affected by the incidence of the competing risk, decisions about the value of the models are not likely to be affected because the model remains of value over a wide range of threshold probabilities.
  
  
  CONCLUSIONS
  The model is not completely accurate, but it demonstrates a modest level of discrimination, adequate calibration, and meaningful net benefit gain for prediction of locoregional failure after radical cystectomy.
authors.affiliation: Department of Urology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ja Hyeon
authors.initials: JH
authors.lastname: Ku
authors.affiliation: Department of Urology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Myong
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Urology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Chang Wook
authors.initials: CW
authors.lastname: Jeong
authors.affiliation: Department of Urology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Cheol
authors.initials: C
authors.lastname: Kwak
authors.affiliation: Department of Urology, Seoul National University College of Medicine, Seoul, Korea. Electronic address: hhkim@snu.ac.kr.
authors.forename: Hyeon Hoe
authors.initials: HH
authors.lastname: Kim
mesh_terms: D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000401:mortality / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D016001:Confidence Intervals; D015653:Cystectomy / Q000379:methods / Q000401:mortality; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D010388:Pelvis; D056910:Republic of Korea; D018570:Risk Assessment; D015996:Survival Rate; D017211:Treatment Failure; D001749:Urinary Bladder Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*