Bladder Preservation in Muscle-Invasive Bladder Cancer: A Population-Based Analysis from British Columbia.

Bladder cancer is the 5th most common cancer in Canada and a quarter of diagnosed patients have muscle-invasive bladder cancer (MIBC). Standard treatment options, systemic therapy and radical cystectomy (RC) are associated with high rates of adverse outcomes. Recently, trimodal treatment (TMT), a bladder preservation strategy defined as maximal transurethral resection of bladder tumor (TURBT) and chemoradiation, has been considered an alternative per guidelines for select patients who prefer bladder preservation or those with comorbidities. Nevertheless, the uptake of bladder preservation strategies in Canada remains low. We conducted a retrospective evaluation in British Columbia (BC) to assess the real-world outcomes of bladder-sparing radiotherapy. Cohort treated with combined chemoradiotherapy (concurrent and/or adjuvant, neoadjuvant chemotherapy) showed numerical improvements across all evaluated endpoints, including disease-specific survival and progression-free survival, compared with radiation therapy alone, which is generally considered an inferior strategy. However, these differences did not reach statistical significance, contrasting with the literature. Despite the limitations posed by the small sample size and the study's retrospective design, the findings highlight the pivotal role of appropriate patient selection in achieving meaningful therapeutic outcomes. Future studies integrating biomarker-driven strategies are needed to enhance outcomes through individualized treatment selection, particularly for older patients with multiple comorbidities.