Clinical Research Directory

Inclusion Criteria: * Men and women, age 40 years or older with endoscopic removal (snare or forceps polypectomy; endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) with R1 (resection margin \<0.1mm23,40) or Rx resection margins of colon cancer (location proximal to the rectum (12 cm or more from the anal verge)) * No contraindication for colon surgery as deemed by the multidisciplinary tumor board (MTB) at the participating centre * Absence of the following histopathological tumor features: poor differentiation, lymphovascular invasion, tumor budding grade B2-B3. * No sign of disease beyond stage T1N0M0 on standard-of-care computed tomography imaging of the thorax, abdomen and pelvis41 and clinical evaluation * Identifiable resection site with colonoscopy, either by visualizing a previously administered tattoo or by identification of a scar in the correct colon segment * No other tumors or polyps larger than 10 mm in diameter in the colorectum at time of randomization * Complete colonoscopy with adequate quality of bowel preparation (Boston Bowel Preparation Scale score ≤2 in all colonic segments) and photo or video documentation of the appendiceal orifice or ileocecal valve. * No colonic strictures or severe diverticulosis. * No prior CRC * No other malignant disease which is not deemed cured * No confirmed or suspected genetic cancer syndrome (10 or more adenomas/serrated lesions, adenomatous or serrated polyposis syndrome; Lynch or Lynch-like syndrome) * No inflammatory bowel disease * Written informed consent provided by before enrolment Exclusion Criteria: * all who do not fulfill inclusion criteria