The aim of the present study is to compare polyp detection rates of LCI with high-definition white light endoscopy (HD-WLE) in patients with Lynch syndrome in a parallel, international, multicenter, randomized controlled colonoscopy trial

Rationale: Linked Color Imaging is a push-button endoscopic imaging technique developed to enhance the visibility of the vasculature and architecture of the mucosal surface by narrowing the spectrum of absorbed light. Compared to High-Definition White Light Endoscopy, mucosal surface patterns are better visualized and this could potentially increase the detection of polyps by improving the visibility of colorectal polyps. Patients with Lynch syndrome have accelerated carcinogenesis and even the smallest polyps have malignant potential. Increasing polyp detection rates with new imaging techniques is therefore of importance.

Objective: To compare polyp detection rates of Linked Color Imaging with High-Definition White Light Endoscopy during surveillance colonoscopy in Lynch patients Study design: international, multicentre, parallel, randomized controlled trial Inclusion criteria: Patients diagnosed with Lynch syndrome (proven germline mutation in one of the following MMR genes: MLH1, MSH2, MSH6 or PMS2) aged ≥ 18 years old undergoing surveillance colonoscopy Exclusion criteria: Patients who underwent recent surveillance colonoscopy within 1 year from current exam (e.g. after piecemeal EMR) or patients referred for endoscopic evaluation of known colorectal neoplasia. Patients in whom the colonoscopy is planned for the evaluation of symptoms like rectal blood loss, recent change in bowel habits, weight loss or anemia. Patients with a concurrent diagnosis of (serrated) polyposis syndrome or inflammatory bowel disease. Patients who are unwilling or unable to give informed consent.

Intervention: Included patients will undergo surveillance colonoscopy with either Linked Color Imaging colonoscopy or High-Definition White Light Endoscopy after 1:1 randomization.

Main study parameters/endpoints: Polyp detection rate of Linked Color Imaging versus High-Definition White Light Endoscopy Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Each colonoscopy is associated with a small, but not negligible risk of bleeding (~1.5%) or perforation (~0.1%). The use of LCI does not increase the risk of endoscopy.

Inclusion Criteria:

• Diagnosis of Lynch-syndrome, with a germline mutation in one of the MMR genes (MLH1, MSH2, MSH6, PMS2)
• Age >18 years
• Surveillance colonoscopy for Lynch syndrome.

Exclusion Criteria:

• Recent surveillance colonoscopy within 1 year from current exam (e.g. after piecemeal EMR) or patients referred for endoscopic evaluation of known colorectal neoplasia.
• Colonoscopy planned for the evaluation of symptoms like rectal blood loss, recent change in bowel habits, weight loss or anemia.
• Patients with a concurrent diagnosis of (serrated) polyposis syndrome or inflammatory bowel disease.
• Patients who are unwilling or unable to give informed consent.