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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

NCT07230639 · Status: RECRUITING · Phase: PHASE2 · Type: INTERVENTIONAL · Enrollment: 52

Last updated 2025-12-26

No results posted yet for this study

Summary

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. Based on these findings, our study aims to evaluate whether lymph node-sparing hypofractionated radiotherapy (25 Gy/5F or 24 Gy/4F) followed sequentially by chemotherapy and PD-1 blockade can increase the pCR rate, improve tolerability, and ultimately enhance outcomes in patients with pMMR/MSS high-risk locally advanced colon cancer.

Conditions

  • Neoadjuvant Therapies
  • Immune Checkpoint Therapy
  • Radiotherapy

Interventions

COMBINATION_PRODUCT

Node-Sparing Radiotherapy(25Gy/5F) plus Chemotherapy and PD-1 inhibitor

Patients will receive node-sparing modified short-course radiotherapy(25Gy/5F), followed by 4 cycles of CAPOX chemotherapy combined with a PD-1 inhibitor. After neoadjuvant treatment, patients will undergo surgery.

COMBINATION_PRODUCT

Node-Sparing Radiotherapy(24Gy/4F) plus Chemotherapy and PD-1 inhibitor

Patients will receive node-sparing modified short-course radiotherapy(24Gy/4F), followed by 4 cycles of CAPOX chemotherapy combined with a PD-1 inhibitor. After neoadjuvant treatment, patients will undergo surgery.

Sponsors & Collaborators

  • Sixth Affiliated Hospital, Sun Yat-sen University

    lead OTHER

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
18 Years
Max Age
75 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2025-08-30
Primary Completion
2030-08-29
Completion
2031-12-31

Countries

  • China

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07230639 on ClinicalTrials.gov