Constructing prognostic model incorporating the 2004 WHO/ISUP classification for patients with non-muscle-invasive urothelial tumours of the urinary bladder

Abstract

Aim To construct a prognostic model for recurrence-free survival (RFS), progression-free survival (PFS) and cancer-specific survival (CSS) for patients who have undergone transurethral resection of non-muscle-invasive (pTa/pT1) urinary bladder urothelial tumours. Methods 1366 patients who had undergone transurethral resection of primary non-muscle-invasive urothelial tumours (pTa, 891 patients; pT1, 475 patients) confined to the bladder were retrospectively studied. Tumours were classified according to the 2004 WHO/International Society of Urologic Pathology grading system. Kaplan–Meier and stepwise Cox regression models were applied, and 200 bootstrap resamples were used to generate survival estimates and 95% CIs. A nomogram was developed that incorporated significant variables predicting survival. Results RFS, PFS and CSS probabilities for non-muscle-invasive bladder urothelial tumours were calculated. Incorporating salient prognostic factors (tumour grade, pT stage, patient age, status of intravesical instillation), the model satisfactorily predicted PFS (concordance index=0.79) and CSS (concordance index=0.87). Conclusions Robust nomograms were created to predict PFS and CSS. These data provide an overall perspective of disease outcomes which may aid in developing individualised follow-up programmes.