3354 - Neoadjuvant Chemotherapy vs. Antibody Drug Conjugate/Immune Checkpoint Inhibitor Prior to Tri-Modality Treatment for Selected Patients with Muscle-Invasive Bladder Cancer
Presenter(s)
S. B. Qin1, X. S. Gao1, T. Cheng1, Y. Bai1, H. Z. Li1, W. Yu2, H. Hao2, C. J. Zhang2, L. Yao2, and Z. S. He2; 1Department of Radiation Oncology, Peking University First Hospital, Beijing, China, 2Department of Urology, Peking Universtiy First Hospital, Beijing, China
Purpose/Objective(s):
Neoadjuvant chemotherapy has been established as the standard of care for patients with muscle-invasive bladder cancer (MIBC) undergoing radical cystectomy. Recently, some studies showed that combination of Antibody Drug Conjugate (ADC) and Immune Checkpoint Inhibitor (ICI) was superior to conventional cisplatin-based chemotherapy in metastatic and locally advanced bladder cancer patients. For patients who undergo bladder preservation with Tri-modality treatment (TMT), however, the benefit of chemotherapy versus ADC/ICI remains controversial.
Materials/Methods:
From Dec. 2023 to Jan. 2025, a total of 30 consecutive patients with cT2-4N0-1M0 bladder cancer underwent neoadjuvant cisplatin-based chemotherapy or ADC/ICI regimes, and Complete response (CR) or partial response (PR) were observed. Patients who have the intention to preserve their bladder received TMT regime. SABR to the tumor or tumor bed in the bladder followed by conventionally fractionated RT (CFRT) to pelvis and total bladder with concomitant weekly radio-sensitizing chemotherapy. Response rate was assessed by cystoscopic evaluation and pelvic MRI or CT. Toxicities were reported per the RTOG acute and late Radiation Morbidity Scoring Schema.
Results:
The median age of all patients was 68 years (58-88 years). All patients received the median 4 cycles of neoadjuvant treatment, and 50% of patients received each of the two treatments. All patients received planned TMT regimes. After a median follow-up time of 14 months, the rate of local control (LC) at 1 years was 100%. The overall survival (OS) and progression free survival (PFS) rates at 1 years were 96% and 87%, respectively. All patients have a disease-free and functioning bladder. PFS at 1 year for patients received cisplatin-based chemotherapy and ADC/ICI were 100% and 76%, respectively. Acute grade 3 gastrointestinal (GI) or genitourinary (GU) toxicities occurred in only 3% of the patients. No = G3 hematologic and dermal toxicities were reported.
Conclusion:
Neoadjuvant treatment including cisplatin-based chemotherapy or ADC/ICI prior to TMT was found to be a well-tolerable and effective strategy for MIBC patients who desire bladder preservation. Patients who received ADC/ICI showed probable benefit of PFS, but long-term follow-up and randomized study were required to further evaluate it.