The study aims to retrospectively investigate the endoscopic resection procedures of cancerous and precancerous lesions of the upper and lower digestive tract in order to evaluate the efficacy and safety outcomes and to compare different resection techniques. In particular, the resection techniques investigated will be mucosectomy, en bloc and piecemeal, endoscopic submucosal dissection (ESD) and its variants, full-thickness resection. The anatomical districts involved will be the esophagus, stomach, duodenum, colon and rectum.