Predicting bladder cancer recurrence and progression: EORTC risk score external validation and the Sao Paulo Cancer Institute Classification

Abstract

Introduction: Risk classification based on predictive factors of bladder cancer recurrence and progression is essential for management decision. Risk tables combine these variables for clinical practice use. European Organization for Research and Treatment of Cancer (EORTC) risk tables are widely accepted for this purpose, however they were never tables and create a risk classification based on our population. Methods: Retrospective study of 561 patients who underwent transurethral resection of superficial bladder from February 2005 to June 2011. Variables analyzed were the same as EORTC risk tables. Logistic regression was performed using SPSS. ROC curve analysis was used for determining the cut-off for tumor size. Results: EORTC risk tables were not able to predict neither disease recurrence nor progression. In our analysis for predicting bladder cancer recurrence alone, we found that T stage and tumor size predicted outcome. Tumor size cut-off was defined as < 4 cm vs ≥ 4 (AUC=0.61; p=0.001). We created a scoring classification: Ta/CIS=0 points, T1=4 points, tumor size=0 or 3 points. Risk classification was obtained by adding the points accordingly and the following recurrence rate at 2 yrs by group: score 0=11.2%; score 3=20.7%; score 4=29.2%; score 7=37.9%. The statistical model for bladder cancer recurrence or progression found that T stage and tumor size predicted the outcome. The scoring classification was: Ta/CIS=0 points, T1=2 points, tumor size=0 or 2 points. Risk classification was obtained by adding the points accordingly and the following recurrence rate at 2 yrs by group: score 0=17%; score 2=28.6%; score 4=40.7%. Conclusions: We found that EORTC risk tables could not predict bladder cancer recurrence or progression in our patient population, possibly due to differences in patient characteristics. Therefore, we developed a new risk classification to aid urologists to individualize the management decision per patient.