Intraoperative Assessment of Distal Resection Margins Using Frozen Section in Mid and Low Rectal Cancer Surgery

This study aims to improve the safety of distal surgical margins in patients with middle and low rectal cancer who receive neoadjuvant radiotherapy. Although magnetic resonance imaging and colonoscopic evaluation after neoadjuvant radiotherapy may suggest complete or near-complete tumor regression, residual tumor cells can still be present in the submucosal and muscular layers of the rectal wall. This may increase the risk of inadequate surgical margins and local recurrence. In this study, patients with middle and low rectal cancer who are scheduled for surgery after neoadjuvant radiotherapy will be randomized into two groups. In the frozen section group, intraoperative frozen section analysis of the resection specimen will be performed immediately after specimen removal to assess the distal resection margin, and the surgical procedure will be guided according to the frozen section results. In the control group, standard surgical resection will be performed without intraoperative frozen section evaluation. Pathological findings, distal margin status, operative time, tumor stage, and recurrence during follow-up will be compared between the two groups to evaluate the impact of intraoperative frozen section analysis on surgical margin safety and oncological outcomes.

NCT Number	NCT07398716
Lead Sponsor	Bakirkoy Dr. Sadi Konuk Research and Training Hospital
Conditions	Rectal Cancer
Enrollment	99 participants
Start Date	2022-01-01
Primary Completion	2025-01-01 (estimated)
Study Completion	2026-01-01 (estimated)
Updated on ClinicalTrials.gov	2026-02-11