Phase II Study of Node-Sparing Short-Course Radiation with Total Neoadjuvant CAPOX and Sintilimab for MSS Locally Advanced Middle and Low Rectal Cancer

What this Trial Is About

Researchers are evaluating a phase II clinical trial for patients with microsatellite stable MSS locally advanced middle and low rectal cancer. The study aims to assess the effects of node-sparing short-course radiation combined with total neoadjuvant chemotherapy using CAPOX capecitabine and oxaliplatin plus the PD-1 inhibitor sintilimab. The primary goal is to measure the complete response rate, including both clinical and pathological response, while also analyzing organ preservation, tumor regression, survival rates, and side effects. Participants will receive node-sparing short-course radiation targeting the tumor bed without irradiating surrounding lymph nodes, given as 5 daily doses of 5 Gy each. Alongside radiation, patients will get six cycles of CAPOX chemotherapy every 3 weeks, with oxaliplatin given intravenously on day 1, capecitabine taken orally twice daily from days 1 to 14, and sintilimab administered intravenously on day 1 of each cycle. Patients achieving a clinical complete response will follow a watch-and-wait strategy, while others will undergo laparoscopic or robotic total mesorectal excision surgery. During the study, participants will be closely monitored with evaluations including tumor response assessments within 10 days after therapy or surgery. Additional follow-up will include measuring tumor regression grade, local recurrence, disease-free survival, overall survival over three years, and quality of life assessments using specific questionnaires at multiple time points up to five years. Adverse effects will also be tracked from treatment start through a five-year period, ensuring comprehensive safety and outcome monitoring throughout the trial.

Node-sparing Radiotherapy Combined With Total Neoadjuvant CAPOX and Sintilimab for MSS Middle and Low Rectal Cancer