The Combination of Hypofractionated Radiotherapy and Immunotherapy in Locally Recurrent Rectal Cancer

The study is a prospective, single-center, single-arm, two-cohort, phase II clinical trial. Patients aged 18 years or older who had pelvic recurrence rectal cancer with or without resectable distant metastasis, with treatment naive disease (cohort A) or progressive disease after first-line chemotherapy (cohort B), Eastern Cooperative Oncology Group performance status of 0-1, will receive 25-40Gy/5Fx irradiation or 15-30Gy/5Fx reirradiation (pelvic radiation history), 18 weeks toripalimab and investigator's choice of chemotherapy +/- target therapy, and stereotactic ablative radiotherapy (SABR) for all metastatic lesions between chemoimmunotherapy cycles, followed by multidisciplinary team (MDT) for decision:follow-up of complete response (CR), radical surgery, sustained treatment of non resection, or exit. The primary endpoint was local objective response rate. Secondary endpoints were extrapelvic objective response rate, R0 resection rate, duration of response, progression-free survival, overall survival, and safety and tolerability of the treatment. Shanghai Junshi Biomedical Technology Co., Ltd. Provides the first three cycles of toripalimab for free and has purchased liability insurance for clinical trial subjects.