Follow-up After Oncological Resection by Endoscopic Colorectal ESD (Endoscopic Submucosal Dissection)

Inclusion Criteria: * Adult patient (18 years or older). * Presumed diagnosis of localized superficial colorectal cancer (T1) during endoscopy using the Conecct classification, confirmed by subsequent histopathological analysis. * Patient included in the French Colorectal ESD Cohort in Experts Centers (FECCo registry) since September 2019 for submucosal dissection. * Histological analysis of the resection specimen revealing a superficial colorectal adenocarcinoma with high risk of lymphatic recurrence, defined by at least one of the following criteria: submucosal invasion depth ≥ 1000 microns, tumor budding grade ≥ 2, presence of lymphatic and/or vascular emboli. Exclusion Criteria: * History of Crohn's disease (ICD-10: K50) or ulcerative colitis (ICD-10: K51). * History of familial adenomatous polyposis and/or genetic predisposition to colorectal cancer (ICD-10: D12.6+0/1/2/4/5 and 6). * Malignant tumor of the colon staged ≥ T2. * Patients not included in the FECCo registry. * Documented objection through the non-opposition form following review of the information notice