Multiple recurrences and risk of disease progression in patients with primary low-grade (TaG1) non-muscle-invasive bladder cancer and with low and intermediate EORTC-risk score.

AIM:To assess the prognostic value of multiple recurrences on the risk of progression in a large cohort of TaG1 bladder cancer of low and intermediate risk based on the EORTC score and to evaluate prognostic factors of multiple recurrences. MATERIALS AND METHODS:We retrospectively analyzed a French cohort of 470 patients with primary TaG1 bladder cancer diagnosed between 1986 and 2010 and followed until 2012. They were classified at low and intermediate risk using the EORTC risk score. Associations between the number of recurrences and the risk of progression to high grade Ta/T1 bladder cancer and progression to muscle-invasive disease were assessed. The characteristics of recurrences, as occurrence time or localization, and risk of other recurrences were evaluated. RESULTS:Out of 470 patients, 251 had recurrence, 34 progressed to high grade Ta/T1 and 17 to muscle-invasive disease, including 4 who had non muscle-invasive progression first. The median follow-up was 7.2 years (interquartile range: 4.2-10.9). In half the progressions, no previous recurrence was observed. No association between the number of recurrences and the risk of progression was detected. Even after 5 years free of event, patients had a 15% risk of recurrence. History of two or more recurrences increased by 4.5 the risk of subsequent recurrence. Time between two recurrences inferior to six months and multifocal localization increased the risk of recurrence. CONCLUSION:Surveillance of patients with TaG1 should be continued beyond 5 years of follow-up. However, cystoscopy exams could be spaced after 5 years. Multiple TaG1 recurrences did not appear to be prognostic for disease progression, but increased significantly the risk of subsequent recurrences. Short time between two recurrences and multifocal localization may serve to adapt monitoring of patients with TaG1 Bladder cancer.