Most colorectal cancer arises from adenomatous polyps. This gradual process may be interrupted by screening and treatment using colonoscopy and polypectomy. Advances in imaging platforms have led to classification systems that facilitate prediction of histologic type and both stratification for and prediction of the risk of invasion. Endoscopic treatment should be the standard of care even for extensive advanced mucosal neoplasm. Technique selection is influenced by lesion features, location, patient factors, and local expertise. Postprocedural complications are more common following advanced resection and endoscopists should be familiar with risk factors, early detection methods, and management.