MP24-10 NO SURVIVAL DIFFERENCE BETWEEN PATIENTS WITH DE NOVO MUSCLE-INVASIVE BLADDER CANCER COMPARED TO THOSE THAT PROGRESS IN ROUTINE CLINICAL PRACTICE

Abstract

INTRODUCTION AND OBJECTIVE: Although consensus frequently suggests that patients who progress to muscle-invasive bladder cancer (MIBC) have worse outcomes than those that present de novo, contemporary studies have been equivocal. The concept is important not only with respect to understanding the biology of the disease but also clinical decision making. The primary objective of this study was to determine if there is a difference in cancer-specific (CSS) and overall survival (OS) between radical cystectomy (RC) patients who presented either with de novo MIBC or those patients who progressed to MIBC. METHODS: This retrospective population-based study reports early and late outcomes of all patients treated within Ontario during 2009-2013 based on their presentation of bladder cancer (de novo vs. progression from non-invasive disease). All incident cases that underwent RC were identified using the Ontario Cancer Registry (OCR) and linked to treatment records. Records from the Canadian Institute for Health Information were used to identify those patients treated with RC. As stage of disease was not routinely available, a team of trained data abstractors obtained and reviewed surgical pathology reports for all RC cases. Statistical analysis of the survival data was performed using the Kaplan-Meier method and Cox proportional hazards were used to adjust for known confounders. RESULTS: 1573 patients underwent RC between 2009 and 2013 in the province of Ontario. 893 were diagnosed with de novo MIBC and 79% had clinical T2 or greater disease at the time of TURBT. 680 were identified as progressors, and 49% had clinical T2 or greater disease at the time of TURBT. Further, neoadjuvant chemotherapy was received by 17% and 13% of de novo patients and progressors respectively. Several process indicators and early outcomes spread to be equivalent between the cohorts including 30 day mortality with a hazard ratio of 1.69 (95% CI 0.90-3.19). There was improved CSS and OS for progressors compared to de novo MIBC patients with hazard ratios of 0.85 (95% CI 0.74-0.98) and 0.90 (95% CI 0.79-1.03) respectively in unadjusted analysis for the whole cohort. However, when controlled for patients with only clinical T2 or greater disease, there was no difference in either CSS or OS between groups in adjusted analysis. CONCLUSIONS: This study shows, when controlled for clinical stage, no significant difference in CSS or OS between patients with de novo MIBC and progressors of MIBC in routine clinical practice. Source of Funding: none