An interventional study of Blood Collection for ctDNA Analysis in Advanced Colorectal Laterally Spreading Tumours (LSTs), sponsored by Centre hospitalier de l'Université de Montréal (CHUM). Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-20.
Sponsored by Centre hospitalier de l'Université de Montréal (CHUM) · Not applicable, Interventional, and Diagnostic
The goal of this prospective interventional biomarker development and validation study is to determine whether circulating tumour DNA (ctDNA) can be detected in patients with large pre-neoplastic colorectal lesions undergoing endoscopic resection and whether ctDNA can be used to identify local recurrence after resection.
The main questions it aims to answer are:
Participants will:
The study does not alter the standard clinical management, resection technique, or surveillance schedule. The only study-specific procedures are blood sample collections performed during routine intravenous catheter placement for the participant's endoscopic procedures.
Exclusion Criteria:
Participants with large colorectal laterally spreading tumours (LSTs) undergoing standard-of-care endoscopic resection will provide blood samples before resection. Tumour tissue and blood samples will be analyzed to develop and evaluate a patient-specific circulating tumour DNA (ctDNA) assay for detection of advanced pre-neoplastic colorectal lesions and local recurrence after resection.
Diagnostic Test: Blood Collection for ctDNA Analysis
Blood samples will be collected before endoscopic resection for circulating tumour DNA (ctDNA) analysis. Results will be correlated with tumour tissue sequencing findings and surveillance colonoscopy outcomes.
Pre-resection ctDNA Detection Rate
Detection of circulating tumour DNA (ctDNA) in the pre-resection plasma sample using a tumour-informed assay. A positive result is defined according to the prespecified threshold for detected tumour-specific variants. The primary outcome is the proportion of evaluable lesions with detectable ctDNA prior to endoscopic resection.
Time frame: Baseline
Local recurrence according to pre-resection ctDNA status
Proportion of patients with local recurrence at the first surveillance colonoscopy stratified by pre-resection ctDNA status (positive vs negative).
Time frame: 6 months
Quantitative pre-resection ctDNA signal
Distribution of quantitative plasma ctDNA measurements (variant allele fraction and/or tumor molecules per mL) in evaluable lesions.
Time frame: Baseline
ctDNA detection rate by lesion characteristics
Pre-resection ctDNA detection rate according to lesion size, histology, dysplasia grade, morphology, and location.
Time frame: Baseline
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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Centre hospitalier de l'Université de Montréal (CHUM)