Population-based analysis of perioperative chemotherapy use, interventions requiring hospitalization and atheroembolic events among patients with non-metastatic muscle-invasive bladder cancer.

Introduction: Utilization of neoadjuvant chemotherapy (NC) in muscle invasive bladder cancer (MIBC) is increasingly recognized as standard of care but trends of use in Ontario remain unknown. Currently, there remains knowledge gaps regarding the effects of perioperative chemotherapy on the rates of interventions requiring hospitalization (IRH) and atheroembolic events (ATEs).

Methods: We conducted a population-based retrospective study within the province of Ontario over 16 years. Patients with non-metastatic MIBC receiving surgery only or planned for perioperative chemotherapy were included. Primary outcomes included 2-year IRH and ATE rates. Univariate/multivariate analysis was used to identify predictors associated with IRHs and ATEs. Cochrane-Armitage was used to assess treatment trends over time.

Results: Our study included 3281 patients. RC alone occurred in 2030 (60.9%), NC in 974 (29.6%) and adjuvant chemotherapy in 8.4% (n = 277). A total of 490/974 (50.3%) patients whom initiated NC with RC intent failed to undergo RC. This improved to 20.5% by 2015 (p < 0.001). Use of NC increased by an absolute value of 33% (p < 0.001). Overall, 4.2% of patients experienced IRHs and 11.5% ATEs. On multivariate analysis, advanced age and Charlson index score (CI) were strong predictors of outcomes, not timing of perioperative chemotherapy (p < 0.05.) CONCLUSION: A total of 29.6% of MIBC patients are planned for NC with 20.5% not progressing to their surgery. Use of NC has substantially increased over time. IRHs and ATEs remain stubbornly high at 4.2% and 11.5% respectively. Older age and higher CI scores are the strongest predictors of IRHs and ATEs (p < 0.05), not perioperative chemotherapy.