Comparing quadrant-based, subtotal, and total intersphincteric resections for ultra-low rectal cancer

Comparative Study on the Short- and Long-term Efficacy of Q-ISR, Traditional Sub-ISR, and t-ISR

Phase 2 Interventional Fudan University · NCT07371273

This compares a quadrant-tailored intersphincteric resection to subtotal and total ISR to see if it preserves anal function without compromising cancer control in people with ultra-low rectal cancer who are candidates for sphincter-preserving surgery.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorFudan University Academic / other
Locations1 site (Shanghai)
Trial IDNCT07371273 on ClinicalTrials.gov

What this trial studies

This phase 2 interventional comparison enrolls patients with ultra-low rectal cancer undergoing sphincter-preserving surgery and assigns them to quadrant-based ISR (Q-ISR), traditional subtotal ISR (Sub-ISR), or total ISR (t-ISR). Short-term endpoints focus on perioperative safety measures such as operative time, blood loss, length of stay, and postoperative complications including Clavien-Dindo grade ≥II and anastomotic issues. Long-term endpoints evaluate anorectal function after stoma closure using LARS and Wexner scores and oncologic outcomes including R0 resection rates, recurrence patterns, and survival. The study is conducted at Fudan University Shanghai Cancer Center and targets tumors that are small, ultra-low, and not invading the intersphincteric plane.

Who should consider this trial

Good fit: Ideal candidates are people with ultra-low rectal cancer whose tumor edge lies 1.5–2.0 cm from the dentate line, tumor length <3 cm, less than one-third circumferential involvement, good preoperative anal function, ASA score ≤3, and no distant metastasis.

Not a fit: Patients with distant metastases, undifferentiated or mucinous histology, tumors infiltrating the intersphincteric space, or larger/more circumferential tumors are unlikely to benefit from the quadrant-based approach.

Why it matters

Potential benefit: If successful, the quadrant-tailored approach could better preserve anal function while maintaining tumor control and reduce the likelihood of permanent stoma.

How similar studies have performed: Conventional and subtotal ISR have prior clinical data showing feasible oncologic outcomes but variable functional recovery, while the quadrant-based Q-ISR approach is relatively novel with limited published evidence to date.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* (1) Rectal cancer diagnosed by digital rectal examination, colonoscopy, and combined biopsy pathology. (2) The distance from the lower edge of the tumor to the dentate line is 1.5-2.0 cm. (3) Good anal function before surgery. (4) The tumor does not infiltrate the intersphincteric space. (5) The tumor length is less than 3 cm, and the proportion of the tumor occupying the intestinal lumen is less than 1/3 of the circumference. (6) American Society of Anesthesiologists (ASA) score is ≤3.

Exclusion Criteria:

* (1) Presence of distant metastasis. (2) Undifferentiated carcinoma or mucinous adenocarcinoma.

Where this trial is running

Shanghai

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Colorectal Cancer
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.