NCT07230639
Node-Sparing Hypofractionated Radiotherapy Plus Chemotherapy and PD-1 Inhibitor in pMMR/MSS High-Risk Locally Advanced Colon Cancer: A Prospective, Randomized, Phase II Trial
Recruiting · Phase 2 · Sixth Affiliated Hospital, Sun Yat-sen University · registry updated 2025-12-26
Inclusion and exclusion lines below are quoted from ClinicalTrials.gov. No match score is shown, because a score needs a person's age, biomarkers, and treatment dates. Confirm the record with the study team.
Most colorectal cancers are microsatellite stable (MSS) or mismatch repair-proficient (pMMR) subtypes, which show limited efficacy to PD-1 inhibitors. Radiotherapy can enhance the release of tumor-associated antigens, thereby improving the responsiveness of pMMR/MSS colorectal cancers to PD-1 blockade. Tumor-draining lymph nodes (TDLNs) are critical sites where PD-1 inhibitors exert their antitumor effects; however, previous studies have reported that direct radiation-induced damage and fibrosis may impair lymphatic drainage and antitumor immunity. Early reports have demonstrated a remarkable pathological complete response (pCR) rate of 77.8% with lymph node-sparing short-course radiotherapy (25 Gy in 5 fractions) in locally advanced rectal cancer. In metastatic colorectal cancer, single-fraction high-dose irradiation (6-8 Gy) has been shown to induce robust abscopal effects....
Inclusion
- Voluntarily signs a written informed consent form.
- Age ≥ 18 and ≤ 75 years at enrollment.
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
- Life expectancy \> 2 years.
- Histologically confirmed colon adenocarcinoma (without squamous or sarcomatoid components).
- Tumor biopsy by immunohistochemistry indicating pMMR, i.e., MLH1, MSH2, MSH6, and PMS2 all positive, or genomic testing indicating MSS.
Exclusion
- Suspicious metastatic lesions or the presence of unresectable locally advanced disease, regardless of stage.
- Malignancy other than colorectal cancer within 5 years prior to enrollment. Subjects cured by local therapy for other malignancies (e.g., basal or squamous cell skin cancer, superficial bladder cancer, ductal carcinoma in situ) are not excluded.
- Receipt of any investigational drug or device within 4 weeks prior to the first dose of study drug.
- Intestinal obstruction, perforation, gastrointestinal bleeding, or other conditions requiring emergency surgery.
- Multiple primary colorectal cancers.
- Prior radiotherapy to the pelvis or abdomen.