3378a - The Potential Impact of Immunotherapy on Hypofractionated Trimodality Therapy in Bladder Cancer

12:45pm - 02:00pm PT

Hall F

Screen: 2

POSTER

Presenter(s)

Sravya Koduri, MD, BS - NYU Langone Health, New York, NY

S. Koduri¹, A. S. Wanna², C. Oh³, M. P. Economides⁴, S. Niglio², D. R. Wise⁴, J. Wysock², K. Murray², W. Huang⁵, S. Taneja⁵, T. B. Daniels², A. J. Evans⁶, M. J. Zelefsky², and P. B. Schiff⁶; ¹Department of Radiation Oncology, NYU Langone Health, New York City, NY, ²NYU Langone Health, New York, NY, ³Biostatistics, Department of Population Health, NYU Langone Health, New York, NY, ⁴Department of Medicine, Perlmutter Cancer Center at NYU Langone Medical Center, New York, NY, ⁵Department of Urology, Perlmutter Cancer Center at New York University Grossman School of Medicine, New York, NY, ⁶Department of Radiation Oncology, NYU Langone Health and Perlmutter Cancer Center, New York, NY

Purpose/Objective(s):

Trimodality therapy (TMT), which is composed of surgery, such as transurethral resection of bladder tumor (TURBT), chemotherapy, and radiation therapy (RT), is a mainstay of bladder preservation treatment for muscle-invasive bladder cancer (MIBC). Although surgery followed by radiation with concurrent chemotherapy versus surgery alone has been shown to improve outcomes in bladder cancer, less is known about the role of immunotherapy (IO) in the setting of radiation treatment regimens in MIBC. We present an institutional review of outcomes in patients treated with TMT with hypofractionated RT with or without concurrent and adjuvant IO.

Materials/Methods:

Patients who received hypofractionated radiation regimens of 52-55 Gy in 2.6-2.75 Gy fractions for cT2-cT4 MIBC at our institution were retrospectively reviewed with IRB approval. Patients were documented as having received neoadjuvant chemotherapy, concurrent chemotherapy, and concurrent and consolidative IO. Acute and long-term toxicities were documented in addition to information regarding the development of locoregional, distant recurrences, and bladder preservation. Overall survival (OS), Progression-free survival (PFS), and bladder preservation was recorded using the Kaplan-Meier method.

Results:

Between 2016 and 2024, 49 patients of a median age of 77 (range of 56-97) years met the inclusion and exclusion criteria and were treated with TMT with hypofractionated RT. Nearly all (92%) of patients in this review received concurrent chemotherapy with gemcitabine, while 30 (61.2%) patients received IO and 19 (38.8%) did not.

Median follow up for the entire cohort was 28.9 months and 9 (30%) patients receiving IO and 5 (26.3%) patients not receiving IO died during this timeframe. The 2-year PFS was 69% in the IO group and 60.7% in the no IO group (p = 0.659). The 2-year OS was 86.1% in the IO group and 67% in the no IO group (p = 0.245). Five (17%) patients in the IO group developed locoregional recurrences with a median follow up time of 33.8 months versus 2 (11%) in the no IO group with a median follow up of 14.8 months (p = 0.858). Six (20%) patients in the IO group versus 1 (5.3%) patient in the no IO group developed distant recurrences (p = 0.309). Among the groups, 3 (10%) patients in the IO group went on to require cystectomies secondary to recurrence compared to 0 patients requiring cystectomy in the no IO group.

Conclusion:

The addition of immunotherapy did not demonstrate a statistically significant improvement in OS or PFS at our institution. Interestingly, there may be a trend toward a higher risk of distant recurrence and a greater need for cystectomy with the addition of IO to TMT in this setting. While we wait for the results of prospective studies, our data suggests that the addition of concurrent and adjuvant immunotherapy to TMT with hypofractionated radiation in bladder cancer treatment may not be advantageous compared to TMT alone.