(UroToday.com) The 2023 GU ASCO annual meeting included a session on urothelial carcinoma, featuring a presentation by Dr. Carlos Riveros discussing comparative real-world survival outcomes of muscle-invasive bladder cancer treated with bladder-only versus whole-pelvis concurrent chemoradiation.
Elective nodal irradiation for patients with muscle-invasive bladder cancer undergoing trimodal therapy is controversial. In patients with node-negative (N0) muscle-invasive bladder cancer, the benefit of elective whole-pelvis concurrent chemoradiotherapy compared to bladder-only concurrent chemoradiotherapy has not been demonstrated. Currently, the National Comprehensive Cancer Network (NCCN) guidelines do not recommend whether to include pelvic nodes in the radiation field. Using real-world data from the National Cancer Database (NCDB), Dr. Riveros and colleagues sought to compare the overall survival between bladder-only concurrent chemoradiotherapy and whole-pelvis concurrent chemoradiotherapy for muscle-invasive bladder cancer.
Using the 2019 NCDB Participant User File, the authors identified cases of muscle-invasive bladder cancer diagnosed between 2017 and 2018. Patients were selected with clinical T2-T4N0M0 disease receiving trimodal therapy as first-line treatment. Trimodal therapy was defined as transurethral resection of bladder tumor followed by CCRT: 60–65 Gy of radiotherapy delivered to the bladder with concurrent single- or multiple-agent chemotherapy. Patients were stratified into bladder-only concurrent chemoradiotherapy vs. whole-pelvis concurrent chemoradiotherapy. Overall survival analysis was performed using Kaplan-Meier estimates and multivariable Cox proportional hazards regression analysis. The variables included in the multivariable Cox regression model were:
- Age
- Sex
- Race
- Comorbidity burden (as per the Charlson-Deyo comorbidity index)
- Facility type
- Insurance status
- Median income quartile
- Rurality
- Distance from facility
- Clinical T stage
A total of 605 patients receiving trimodal therapy for muscle-invasive bladder cancer were identified: 162 (26.8%) bladder-only concurrent chemoradiotherapy and 443 (73.2%) whole-pelvis concurrent chemoradiotherapy. Baseline characteristics are as follows:
The median follow-up time was 25.6 months (interquartile range [IQR]: 4.8-42.6) and 28.7 months (IQR: 3.0-51.6) for bladder-only concurrent chemoradiotherapy and whole-pelvis concurrent chemoradiotherapy, respectively. The median overall survival was 32.9 months (95% CI 30.8 – not reached) and 48.3 months (95% CI 39.6 – not reached) for bladder-only concurrent chemoradiotherapy and whole-pelvis concurrent chemoradiotherapy, respectively. However, multivariable Cox regression analysis failed to find an association between whole-pelvis concurrent chemoradiotherapy (HR 1.08, 95% CI 0.76-1.54) and improved overall survival compared to bladder-only concurrent chemoradiotherapy:
Dr. Riveros concluded his presentation discussing comparative real-world survival outcomes of muscle-invasive bladder cancer treated with bladder-only versus whole-pelvis concurrent chemoradiation with the following take-home messages:
- Elective nodal-irradiation (whole-pelvis concurrent chemoradiotherapy) in the setting of trimodal therapy for muscle-invasive bladder cancer was not associated with a benefit in overall survival compared to bladder-only concurrent chemoradiotherapy
Presented by: Carlos Riveros, MD, Department of Urology, Houston Methodist Hospital, Houston, TX
Co-Authors: Sanjana Ranganathan, Waqar Haque, Jiaqiong Xu, Michael Geng, Maryam Anis, Taliah Muhammad, Andrew M. Farach, Bin S. Teh, Christopher J.D. Wallis, Guru P. Sonpavde, Raj Satkunasivam
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2023 Genitourinary (GU) American Society of Clinical Oncology (ASCO) Annual Meeting, San Francisco, Thurs, Feb 16 – Sat, Feb 18, 2023.