Abstract: PD57-12
Sources of Funding: Greenberg Bladder Cancer Institute

Introduction

Patients with muscle-invasive bladder cancer (MIBC) who are down-staged after neoadjuvant chemotherapy (NAC) have improved survival over those who remain ≥pT2. It is uncertain whether subgroups of patients with high-risk non-MIBC (NMIBC) would also benefit from NAC. We compared post-surgical outcomes in high-risk NMIBC patients who did not receive NAC with MIBC patients who were down-staged with NAC and without NAC.

Methods

We identified 334 patients with urothelial bladder cancer who were pT0, pTis, pTa, or pT1 and N0 at cystectomy from 2005-2015: 111 with cT2 who received NAC (NAC-responsive), 37 with cT2 who did not receive NAC (non-NAC-responsive), and 186 with high-grade cTis, cTa, or cT1 (high-risk NMIBC). Comparisons were made using Kruskal-Wallis for continuous and chi-squared for categorical variables. Log-rank and Cox regression analyses were used to evaluate survival.

Results

Compared to NAC-responsive and non-NAC-responsive patients, high-risk NMIBC patients had higher prevalence of intravesical therapy (70.4% vs. 14.1% and 13.5%, p<0.01), pure urothelial histology (92.5% vs. 80.2% and 64.9%, p<0.01), tumor ≥2 cm (19.9% vs. 6.6% and 10.8%, p<0.01), and lower prevalence of pT0 pathology (11.8% vs. 41.3% and 46%, p<0.01). Location of recurrence did not differ significantly between the groups (p=0.53), and 23.5% of recurrences in high-risk NMIBC patients occurred outside of the pelvis. Log-rank comparisons showed improved recurrence-free and overall survival in NAC-responsive vs. high-risk NMIBC patients (p<0.02 and p<0.02) but not in non-NAC-responsive vs. high-risk NMIBC patients (p=0.34 and p=0.43). In Cox regression, tumor ≥2 cm was independently associated with increased risk of cancer recurrence (HR=2.31, p=0.02) and overall mortality (HR=2.10, p=0.02)

Conclusions

Patients with NAC-responsive MIBC had better post-surgical outcomes than patients with high-risk NMIBC. High-risk NMIBC patients had a higher prevalence of tumor ≥2 cm, which was an independant predictor of cancer recurrence. Despite being node negative, almost a quarter of recurrences in patients with high-risk NMIBC occurred distantly. Further work is needed to identify whether patients with unresectable or high volume NMIBC could benefit from NAC.

Funding

Greenberg Bladder Cancer Institute