title: An analysis of patients with T2 renal cell carcinoma (RCC) according to tumour size: a population-based analysis.
abstract: OBJECTIVE
  To examine the discriminant properties of the most contemporary version of the Tumour-Node-Metastasis (TNM) staging for renal cell carcinoma (RCC) sub-classification of T2 lesions according to a threshold size of 10 cm. Other thresholds were also assessed.
  
  
  METHODS
  Between 1988 and 2006, within the Surveillance, Epidemiology, and End Results database, patients with T2 N0-2 M0-1 RCC treated with a nephrectomy were abstracted. Tumour size was evaluated according to several thresholds: ≥8, ≥9, ≥10, ≥11, and ≥12 cm. Kaplan-Meier and life tables for cancer-specific mortality (CSM) were computed. Several Cox regression modes were fitted for prediction of CSM, using different thresholds. The predictive accuracy of various thresholds was compared using the area under the curve and methods of calibration.
  
  
  RESULTS
  In all, 4963 patients were identified. Kaplan-Meier analyses showed statistically significant CSM-free survival differences between all examined thresholds. In multivariable Cox-regression models, all tested tumour size thresholds emerged as independent predictors of CSM. Of all thresholds, the values of 9 (0.55) and 11 cm (0.55) achieved the highest discrimination in univariable analysis, followed by 10 (0.539), 12 (0.539), and 8 cm (0.531). When the thresholds were combined with all other variables, the 11 cm (0.688) achieved the highest discrimination.
  
  
  CONCLUSIONS
  The discriminant properties of all examined thresholds showed very similar discriminant properties, which brings into questioning whether a dichotomization of pT2 tumours is really necessary.
authors: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal, Canada.
authors: Marco
authors: M
authors: Bianchi
authors: Andreas
authors: A
authors: Becker
authors: Quoc-Dien
authors: QD
authors: Trinh
authors: Firas
authors: F
authors: Abdollah
authors: Zhe
authors: Z
authors: Tian
authors: Shahrokh F
authors: SF
authors: Shariat
authors: Francesco
authors: F
authors: Montorsi
authors: Paul
authors: P
authors: Perrotte
authors: Markus
authors: M
authors: Graefen
authors: Pierre I
authors: PI
authors: Karakiewicz
authors: Maxine
authors: M
authors: Sun
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009392:Nephrectomy; D011159:Population Surveillance / Q000379:methods*; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D018426:SEER Program; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology