3198 - Clinical Outcomes of Patients with Histologic Subtypes of Bladder Cancer Treated with Trimodality Therapy
Presenter(s)
A. Bommireddy1, E. Brooks1, C. A. Reddy1, M. Nair1, N. Almassi2, C. Weight2, S. Campbell2, L. Bukavina2, M. C. Ornstein3, A. Nizam3, T. Gilligan3, C. Wee3, S. Gupta4, O. Y. Mian5, and R. D. Tendulkar1; 1Department of Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH, 2Glickman Urologic and Kidney Institute, Cleveland Clinic Foundation, Cleveland, OH, 3Department of Hematology and Oncology, Cleveland Clinic Foundation, Cleveland, OH, 4Cleveland Clinic, Cleveland, OH, 5Department of Radiation Oncology, University of Washington/ Fred Hutchinson Cancer Center, Seattle, WA
Purpose/Objective(s): Bladder preservation with trimodality therapy (TMT) is an alternative to cystectomy for high risk T1 (refractory to BCG) or muscle invasive bladder cancer (MIBC). Limited data exists for outcomes after TMT for urothelial versus other histologic subtypes (HS). We report our institutional outcomes for patients with HS bladder cancer treated with TMT.
Materials/Methods: Patients with high-risk T1 or MIBC who underwent TMT between 2006-2022 were retrospectively reviewed from a single institutional database. Patients were categorized as having either pure urothelial carcinoma (PUC) or another HS as defined by the World Health Organization 2022 classification. Primary endpoint was overall survival (OS); secondary endpoints included local recurrence (LR), disease free survival (DFS), and cancer specific mortality (CSM). Cumulative incidence estimate with Gray’s test was performed for CSM and LR; Kaplan-Meier analysis with log-rank test was performed for DFS and OS. Cox proportional hazards regression was performed to identify predictors of OS.
Results: The study included 225 patients (132 PUC, 93 HS), with a median age of 79 years and median follow-up of 27 months. HS included 38 (41%) squamous, 13 (14%) small cell/neuroendocrine, 7 (8%) micropapillary, 5 (5%) sarcomatoid, 4 (4%) glandular, 3 (3%) plasmacytoid, 11 (12%) multiple subtypes, and 12 (13%) others. Overall, 18 patients (8%) had high risk T1 disease, and 207 patients (92%) had MIBC. There was no difference in clinical T-stage (p = 0.17), tumor size (p = 0.14), presence of carcinoma-in-situ (p = 0.10), and presence of hydronephrosis (p = 0.61) among the two cohorts. Forty-seven patients (36%) with PUC and 32 patients (34%) with HS were cystectomy candidates at diagnosis (p = 0.81). Sixty patients (46%) with PUC and 32 patients (34%) with HS received elective radiation treatment to the regional lymph nodes (p = 0.11). Neoadjuvant or concurrent chemotherapy was administered in 105 patients (80%) with PUC and 75 patients (81%) with HS (p = 0.80). Five-year OS was 32% for PUC vs 40% for HS (p = 0.32); 5-year cumulative incidence of LR was 37% for PUC vs 26% for HS (p = 0.34); 5-year DFS was 36% for PUC vs 52% for HS (p = 0.11); 5-year cumulative incidence of CSM was 21% for PUC vs 23% for HS (p = 0.91). On univariate analysis, age (p < 0.01), cystectomy candidacy (p < 0.01), and neoadjuvant or concurrent chemotherapy (p < 0.01) were significantly associated with OS. On multivariate analysis, age (HR 1.03, 95% CI: 1.00-1.05, p = 0.03), cystectomy candidacy (HR 0.55, 95% CI: 0.37-0.81, p < 0.01), and neoadjuvant or concurrent chemotherapy (HR 0.61, 95% CI: 0.40-0.92, p = 0.02) remained significantly associated with OS.
Conclusion: In this series of patients who underwent TMT for high-risk T1 or MIBC, there were no differences in 5-year OS, LR, DFS, or CSM between PUC and HS cohorts. Bladder preservation with TMT appears to be a reasonable treatment option for patients with HS bladder cancer. Larger studies are warranted, particularly to evaluate individual subtypes.