3270 - Safety and Efficacy of Postoperative Adjuvant Radiotherapy Combined with Immunotherapy in Patients with Upper Tract Urothelial Carcinoma

12:45pm - 02:00pm PT

Hall F

Screen: 6

POSTER

Presenter(s)

Xiaoying Li, MD - Peking University First Hospital, Beijng, Beijing

X. Li¹, X. S. Gao¹, Q. Tang², C. Xu², and X. Li²; ¹Department of Radiation Oncology, Peking University First Hospital, Beijing, China, ²Peking University First Hospital urology department, Peking, China

Purpose/Objective(s):

To analyze the safety and efficacy of adjuvant immunotherapy combined with radiotherapy in patients with muscle-invasive upper tract urothelial carcinoma (UTUC) after surgery.

Materials/Methods:

A prospective analysis was conducted on UTUC patients who underwent radical nephroureterectomy and received postoperative adjuvant immunotherapy combined with radiotherapy at the Department of Urology, Peking University First Hospital from 2021 to 2024. All patients had pathological staging of muscle-invasive disease (=T2) or lymph node metastasis. Patients were divided into concurrent radiation immunotherapy (CRI) and sequential radiation immunotherapy (SRT) groups based on the sequence of radiotherapy and immunotherapy initiation.

Results:

A total of 39 UTUC patients were included in this study, with a median follow-up time of 15 months (range: 3–37 months). All patients received postoperative adjuvant radiotherapy, with 23 patients starting immunotherapy concurrently with radiotherapy and 16 patients starting immunotherapy after completing radiotherapy. No grade 3 or higher adverse reactions were observed in the combined treatment group. Gastrointestinal reactions were the main adverse effects during combined treatment, with 43.6% of patients experiencing grade 1 or higher nausea and vomiting, and 23.1% experiencing grade 2 or higher nausea and vomiting. Grade 1 diarrhea occurred in 23.1% of patients, while 5.2% experienced grade 2 diarrhea. Grade 1 leukopenia was observed in 20.5% of patients, and grade 2 leukopenia occurred in 15.4% of patients. The median follow-up times for the CCRI and SCRT groups were 11 and 16.5 months, respectively. The 1-year progression-free survival (PFS) rates were 95.5% in the CCRI group and 93.8% in the SCRT group. The 1-year PFS rate was 74.1% in patients who received immunotherapy for less than 6 months, compared to 100% in those who received immunotherapy for more than 6 months, showing a statistically significant difference (P=0.01).

Conclusion:

Adjuvant immunotherapy combined with radiotherapy for UTUC after surgery is safe, and preliminary follow-up results indicate a high 1-year progression-free survival rate.