A single malignant colorectal polyp, defined as a colorectal adenocarcinoma invading the submucosa but not the muscularis propria (pT1), arising in an adenomatous or serrated polyp
Endoscopic resection of the malignant polyp by snare polypectomy, endoscopic mucosal resection (EMR), or endoscopic submucosal dissection (ESD)
Pathologic confirmation of the malignant polyp within 90 days before enrollment
