An interventional study of Adjuvant thermal ablation and No adjuvant thermal ablation in Colorectal Cancer and Polyp of Colon, sponsored by Centre hospitalier de l'Université de Montréal (CHUM). Not yet recruiting at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-14.
Sponsored by Centre hospitalier de l'Université de Montréal (CHUM) · Not applicable, Interventional, and Prevention
The goal of this clinical trial is to clarify the role of adjuvant thermal ablation for non-thermal endoscopic mucosal resection (EMR) of large (≥20mm) flat colorectal polyps (so-called laterally spreading lesions [LSLs]).
The hypothesis is that adding adjuvant thermal ablation to non-thermal EMR (vs no ablation) will result in lower lesion recurrence rates at 6-month follow-up, and non-inferior adverse events (AE) rates 14 days post EMR.
For participants with planned EMR, endoscopists will perform non-thermal EMRs as per standard of care and:
This trial is an open-label, two-arm, parallel-group, multicenter RCT with co-primary outcomes (superiority for recurrence, non-inferiority for AEs). Patients undergoing non-thermal EMR will be randomized (1:1) to adjuvant thermal ablation (experimental group) or no ablation (control group).
All participating endoscopists will view dedicated teaching videos of the standard thermal ablation technique and key technical details to ensure consistent study procedures. Patients with planned EMR procedures will be invited by a research assistant before the EMR to participate in the study. Patients will be randomized to control or experimental groups in a 1:1 ratio using a central REDCap randomization module after the EMR resection phase is completed and immediately before adjuvant thermal ablation (intervention). This will limit bias by ensuring that the EMR technique is not affected by group allocation. When 2 or more lesions are present in a patient, the largest lesion will be chosen for inclusion in the study and all lesions will be photodocumented for auditing purposes.
No ablation (control group): Non-thermal EMR will be performed as per standard of care with submucosal injection and non-electrocautery resection of all visually visible polyp tissue using a snare. When the endoscopist determines that the resection is complete, no adjuvant thermal ablation of the post-EMR defect will be performed. Defect closure using clips will be performed only if there is concern for injury to the muscle layer or signs of overt perforation. A tattoo will be placed 3 cm distal to the resected lesion to allow for better identification of the resection site for follow-up. If multiple large polyps are found and removed, the largest lesion (study polyp) will be marked with two tattoos 3 cm distally and 3 cm proximally, to clearly identify the study polyp resection site.
Adjuvant thermal ablation (experimental group): Non-thermal EMR will be performed as per standard of care with submucosal injection and non-electrocautery resection of all visually visible polyp tissue using a snare. When the endoscopist determines that the resection is complete, submucosal injection (0.9% NaCl with methylene blue solution) using the h-APC probe (ERBEJET 2 attached to Vio3 electrosurgical unit, pressure: 40 bar) will be performed to further expose the resection margin. Adjuvant thermal ablation will be applied to the outside margins of the resection site using the h-APC probe. Then, adjuvant thermal ablation will also be applied to the base of the resection site using the h-APC probe. The precise electrocautery mode (PRECISE-APC setting 9) will be used to apply thermal ablation, as previously described for h-APC. Defect closure using clips will be performed only if there is concern for injury to the muscle layer or signs of overt perforation. A tattoo will be placed in the same way as described in the control group and, again, if multiple large polyps are found and removed, the largest lesion (study polyp) will be marked with two tattoos 3 cm distally and 3 cm proximally, to clearly identify the study polyp resection site.
At 6 months after initial colonoscopy, patients will undergo a first follow-up colonoscopy, as suggested by current guidelines and from studies showing that most recurrences occurred within the first 6 months. A window of 3 to 13 months will be permitted for the first follow-up. If recurrence is detected, patients will undergo subsequent colonoscopies at shortened intervals, as determined by the treating endoscopist, until no recurrence is detected. If surgery is performed due to difficulty in treating recurrence, patients will undergo a follow-up colonoscopy 6 months after surgery to detect any possible recurrence. All patients will undergo a second and final study colonoscopy 18 months after randomization, which will also mark the end of study follow-up. The second follow-up may be conducted within a window of 14 to 24 months. Subsequent colonoscopies will then be recommended outside the study as per routine care for such a clinical situation.
6,541 studies on the registry are indexed under Colorectal Neoplasms; 1,667 are open to participants now.
This study's planned enrollment of 752 is above the median of 76 across 4,800 interventional studies indexed under Colorectal Neoplasms.
Browse Colorectal Neoplasms studies →Centre hospitalier de l'Université de Montréal (CHUM) is the lead sponsor of 376 studies on the registry; 110 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant thermal ablation will be applied to the base and outside margins of the resection site after non-thermal EMR.
Procedure: Adjuvant thermal ablation
After non-thermal EMR, no adjuvant thermal ablation will be performed.
Procedure: No adjuvant thermal ablation
When the endoscopist determines that the resection is complete, submucosal injection (0.9% NaCl with methylene blue solution) using the h-APC probe (ERBEJET 2 attached to Vio3 electrosurgical unit, pressure: 40 bar) will be performed to further expose the resection margin. Adjuvant thermal ablation will be applied to the outside margins of the resection site using the h-APC probe. Adjuvant thermal ablation will then also be applied to the base of the resection site using the h-APC probe. The precise electrocautery mode (PRECISE-APC setting 9) will be used to apply thermal ablation, as previously described for h-APC.
After performing non-thermal EMR with thermal ablation, adjuvant thermal ablation will not be performed.
Lesion recurrence rate
Defined as the number of cases with pathology-confirmed hyperplastic, serrated, or adenomatous histology at the tattooed resection site compatible with the study polyp histology divided by the total number of cases.
Time frame: 6 months
Clinically significant adverse event (AE) rate
Defined as the number of cases with delayed bleeding (blood per rectum resulting in emergency room visit, unplanned hospitalization, endoscopic, radiologic, or surgical intervention) and/or delayed perforation (endoscopic or radiologic evidence of significant air or any luminal contents outside the gastrointestinal tract) divided by the total number of cases.
Time frame: 14 days
Any delayed bleeding rate
Defined as the number of cases with blood per rectum, regardless of clinical significance, divided by the total number of cases.
Time frame: 14 days
Lesion recurrence rate at 18-month follow-up
Defined as the number of cases with pathology-confirmed hyperplastic, serrated, or adenomatous histology at the tattooed resection site compatible with the study polyp histology divided by the total number of cases.
Time frame: 18 months
High-grade dysplasia rate at the 18-month follow-up
Defined as the number of cases with high-grade dysplasia on resection scars divided by the total number of cases.
Time frame: 18 months
Rate of CRC during the 18-month follow-up period
Defined as the number of cases with pathology-confirmed carcinomas divided by the total number of cases.
Time frame: From enrollment to the final follow-up colonoscopy at 18 months
Colonoscopies to lesion clearance
Defined as the total number of colonoscopies required to achieve lesion clearance, which means no histologic recurrence at the resection scar on follow-up.
Time frame: 18 months
EMR procedure time
Defined as the length of time required for the initial EMR.
Time frame: 1 day
Rate of delayed bleeding in the proximal colon
Number of cases with clinically significant delayed bleeding in the proximal colon (proximal to the splenic flexure) divided by the total number of cases.
Time frame: 14 days
Defect closure time
Time required for defect closure.
Time frame: 1 day
Rate of technical success for complete defect closure
Number of cases with technical success for complete defect closure (defined as adequate apposition of the mucosal defect margins without visible submucosal areas \>3mm along the closure line) divided by total number of cases.
Time frame: 6 months
Direct Procedural Costs (2025 Canadian Dollars) of Non-Thermal EMR With or Without Adjuvant Thermal Ablation
Total direct procedural costs, expressed in 2025 Canadian dollars, associated with performing the index non-thermal endoscopic mucosal resection (EMR), with or without adjuvant thermal ablation (h-APC). Costs will be calculated based on the tools and devices used during the procedure (e.g., snares, probes, biopsy forceps, pathology sample pots), as recorded by a research assistant for each procedure. Costs will be presented separately for participants who received adjuvant thermal ablation versus those who did not. Unit of Measure : Canadian Dollars (CAD)
Time frame: From enrollment to the final follow-up colonoscopy at 18 months
Plan to share: Yes — Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures and appendices).
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: Beginning 12 months and ending 36 months following article publication.
Access criteria: Proposals should be directed to daniel.von.renteln.med@ssss.gouv.qc.ca. To gain access, data requestors will need to sign a data access agreement.
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This study is not yet recruiting, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
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