Canadian experience of neoadjuvant chemotherapy on bladder recurrences in patients managed with trimodal therapy for muscle-invasive bladder cancer.

Abstract

Bladder preservation with trimodal therapy (TMT) has emerged as a feasible alternative to radical cystectomy in patients with muscle-invasive bladder cancer. Neoadjuvant chemotherapy (NAC) was proven to cause pathological downstaging. For this reason, we evaluated whether receipt of NAC decreases local bladder recurrences in TMT patients. We retrospectively analyzed our TMT database for all patients treated between 2003 and 2017. Patients were treated with maximal transurethral resection of bladder tumor (TURBT) followed by chemotherapy/radiotherapy with or without NAC. Baseline demographic and tumor characteristics were recorded. Rates of local and systemic recurrence were analyzed per receipt of NAC. Overall recurrence-free survival (RFS) and bladder (b)RFS were analyzed using the Kaplan-Meier method and Cox proportional hazards modelling. Median age and followup periods were 72 years and 3.6 years, respectively. Fifty-four patients had NAC and concurrent chemoradiation (NAC-TMT) vs. 70 patients who had concurrent chemoradiation only (TMT). Carcinoma in situ (CIS) was present in 31% of the patients in NAC-TMT group compared to 24% in TMT group (p=0.40). After treatment, 24 (44%) and 31 (44%) patients in NAC-TMT and TMT groups, respectively, had bladder tumor recurrence. Overall RFS at three years was 46% and 50% in NAC-TMT and TMT groups, respectively (p=0.70). BRFS at three years was 55% and 69% in NAC-TMT and TMT groups, respectively (p=0.27). Multivariable analyses found that the presence of concomitant CIS (hazard ratio [HR] 2.13; 95% confidence interval CI 1.06-4.27; p=0.0036) was the primary factor associated with local bladder recurrence. Receipt of NAC does not obviate the risk of bladder recurrence post-TMT. Patients with CIS should be monitored especially closely for local recurrence.