Reducing the Resection Range After Neoadjuvant Therapy for Locally Advanced Upper Rectal and Rectosigmoid Junction Cancers

NCT07038122 | Active Not Recruiting DMC

• 1 other identifier: E2025156
• Study Type: interventional
• Target: 874
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn evaluate the safety and efficacy of reduced surgical resection margins in patients with local advanced upper rectal or rectosigmoid junction tumors who met the ycT≤3N0M0 regression following neoadjuvant therapy. The main questions it aims to answer are: Does reduced surgical resection margins (3 cm of distal margin and 5 cm of proximal margin) meet the radical resection criteria, including the rate of negative resection margin, the number of lymph node harvested? How is the surgical safety of reduced surgical resection, including the surgical duration , bleeding, recovery time and postoperative complications? Is reduced surgical margins resection (3 cm of distal margin and 5 cm of proximal margin) inferior to conventional surgical margins resection (5 cm of distal margin and 10 cm of proximal margin) in terms of oncology safety?

Conditions

Locally Advanced Rectal Carcinoma

Outcome Measures

Primary Outcomes (1)

• 3 years DFS

  3 years Disease Free Survival Rate

  3 year

Secondary Outcomes (7)

• R0 resection rate

  1 year

• Number of lymph node harvested

  1 year

• Surgical duration

  1 year

• Intraoperative blood loss

  1 year

• Anastomotic leakage

  1 year

Study Arms (2)

Conventional resection margins group

OTHER

Conventional resection margins: Refers to the surgical resection region including 10 cm bowel proximal to the tumor, 5 cm bowel distal to the tumor, and lymph node dissection in the corresponding mesentery.

Procedure: Laparoscopic resection; Other: Neoadjuvant Therapy

Reduced resection margins group

EXPERIMENTAL

Reduced resection margins: Refers to the surgical resection region including 5 cm bowel proximal to the tumor, 3 cm bowel distal to the tumor, and lymph node dissection in the corresponding mesentery.

Procedure: Laparoscopic resection; Other: Neoadjuvant Therapy

Interventions

Laparoscopic resection PROCEDURE

Laparoscopic resection of bowel and corresponding mesentery.

Conventional resection margins group; Reduced resection margins group

Neoadjuvant Therapy OTHER

Neoadjuvant Therapy aims to downstage the tumor including different chemotherapy, targeted therapy and immunotherapy.

Conventional resection margins group; Reduced resection margins group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18-80 years.
• Histopathologically confirmed adenocarcinoma of the rectum or rectosigmoid junction.
• Clinical stage cT3-4N+M0, with or without positive mesorectal fascia (MRF), with or without extramural vascular invasion (EMVI); Tumor location confirmed by imaging to be above the peritoneal reflection and by endoscopy to be in the upper rectum or rectosigmoid junction.
• For patients with pMMR (proficient Mismatch Repair; immunohistochemistry shows expression of all four proteins: MSH1, MSH2, MSH6, PMS2) or MSS (Microsatellite Stable) status: Tumor downstaged to T≤3N0M0 after neoadjuvant chemotherapy or total neoadjuvant therapy (TNT). Chemotherapy regimens include, but are not limited to, FOLFOX6, CAPOX, or FOLFOXIRI.
• For patients with dMMR (deficient Mismatch Repair; immunohistochemistry shows loss of expression in two or more of MSH1, MSH2, MSH6, PMS2) or MSI-H (Microsatellite Instability-High) status: Tumor downstaged to T≤3N0M0 after immunotherapy.
• Pre-neoadjuvant therapy / Preoperative staging methods: All patients underwent contrast-enhanced CT for staging. Peri-rectal metastatic lymph nodes: defined as nodes with short-axis diameter ≥10 mm or exhibiting CT characteristics typical of metastasis. Preoperative chest, abdominal CT, and pelvic MRI ruling out distant metastasis.
• No signs of bowel obstruction; OR bowel obstruction that has resolved following proximal diverting colostomy.
• No prior colorectal surgery.
• No prior chemotherapy or radiotherapy.
• No prior treatment with biologic agents (e.g., monoclonal antibodies), immunotherapy (e.g., anti-PD-1, anti-PD-L1, anti-PD-L2, or anti-CTLA-4 antibodies), or other investigational drugs.
• Prior endocrine therapy: Allowed.
• Signed informed consent form.

You may not qualify if:

• History of malignant colorectal tumor(s).
• Requiring emergent surgery (e.g., due to bowel obstruction or intestinal hemorrhage).
• Primary tumor invading adjacent organs/tissues precluding R0 resection.
• Multifocal primary tumors.
• Concurrent diagnosis of other active malignancy.
• Participation in other clinical trials within 4 weeks prior to enrollment or current participation.
• ASA physical status classification ≥ IV and/or ECOG performance status ≥ 2 (see Appendix for details).
• Severe hepatic, renal, cardiopulmonary, or coagulation dysfunction, or significant comorbidities contraindicating surgery.
• History of severe psychiatric disorders.
• Pregnancy or lactation.
• Uncontrolled preoperative infection.
• Other clinical or laboratory conditions deemed by the investigator to render the patient unsuitable for the trial.

Sponsors & Collaborators

• Sixth Affiliated Hospital, Sun Yat-sen University: lead

Study Sites (1)

Sixth Affiliated Hospital, Sun Yat-sen University

Guangzhou, Guangdong, China

Location

MeSH Terms

Interventions

Neoadjuvant Therapy

Intervention Hierarchy (Ancestors)

Combined Modality Therapy; Therapeutics

Study Officials

• Jun Huang, PhD.

  The Sixth Affiliated Hospital, Sun Yat-sen University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: June 18, 2025
• First Posted: June 26, 2025
• Study Start: July 1, 2025
• Primary Completion (Estimated): June 20, 2027
• Study Completion (Estimated): June 20, 2028
• Last Updated: December 18, 2025

Record last verified: 2025-12

Locations

CN (1)