Risk of Metachronous Findings After Detection of Serrated Lesions and High-grade Dysplasia With Surveillance Delay

This study is looking at the risk of developing new concerning findings in the colon (such as advanced polyps or cancer) in people who were overdue for their recommended follow-up colonoscopy after having certain types of polyps (called serrated lesions or high-grade dysplasia) found previously. **You may be eligible if...** - You are between 45 and 80 years old - You had a colonoscopy at the Montreal University Hospital Center between 2009 and 2022 - A serrated lesion or high-grade dysplasia polyp was found at that colonoscopy - You did not have a follow-up colonoscopy within the recommended timeframe **You may NOT be eligible if...** - You have been diagnosed with inflammatory bowel disease - You have a hereditary colorectal cancer syndrome (e.g., Lynch syndrome) - You already had colorectal cancer at the first colonoscopy - You have serrated polyposis syndrome - You have a short life expectancy and would not benefit from colonoscopy - Your follow-up is not yet overdue according to guidelines Talk to your doctor to see if this trial is right for you.