title: Kattan postoperative nomogram for renal cell carcinoma: predictive accuracy in a Japanese population.
abstract: OBJECTIVE
  The aim of the current study was to establish the predictive accuracy of the Kattan postoperative nomogram for non-metastatic renal cell carcinoma (RCC) in a Japanese population.
  
  
  METHODS
  A total of 211 patients with stage T1-3N0M0 clear cell RCC who underwent radical nephrectomy or nephron-sparing surgery between 1991 and 2004 were included in this analysis. Median follow up was 81 months (range: 4-208). Univariate and multivariate analyses were performed, and the influence of age, sex, clinical presentation, T stage, histological tumor size, grade, and microvascular invasion on disease recurrence-free survival (RFS) was determined. For each patient, the prognostic score for 5-year RFS was calculated using the Kattan nomogram. The discriminating ability of this model was assessed by the concordance index, and bootstrapping was used to evaluate confidence intervals.
  
  
  RESULTS
  The 5-year RFS rate for all patients calculated using the Kaplan-Meier method was 80.6%. In multivariate analysis, the statistically significant prognostic factors for 5-year RFS were high-grade tumors (P=0.019) and symptomatic disease (P=0.017). The concordance index for RFS predicted by the Kattan nomogram was 0.735 (95% confidence interval: 0.734-0.736). There was a slight discrepancy between the RFS predicted by the Kattan nomogram and the likelihood of being recurrence-free at 5 years according to the Cox analysis in the current patient population.
  
  
  CONCLUSIONS
  These findings suggest the necessity of constructing a more useful nomogram for predicting the prognosis of Japanese patients with non-metastatic RCC.
authors.affiliation: Division of Urology, Department of Regenerative and Transplant Medicine, Course of Biological Function and Medicine Control, Niigata University Graduate School of Medical and Dental Science, Niigata, Japan. kazuyas@med.niigata-u.ac.jp
authors.forename: Kazuya
authors.initials: K
authors.lastname: Suzuki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishiyama
authors.forename: Noboru
authors.initials: N
authors.lastname: Hara
authors.forename: Kohei
authors.initials: K
authors.lastname: Akazawa
authors.forename: Kota
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D002292:Carcinoma, Renal Cell / Q000208:ethnology* / Q000601:surgery; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007680:Kidney Neoplasms / Q000208:ethnology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009392:Nephrectomy / Q000706:statistics & numerical data; D049451:Nomograms; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D055815:Young Adult