Clinical Outcomes After Non-curative Endoscopic Resection in Early Colorectal Cancer: A Multicenter Study

Inclusion Criteria: * Age ≥18 years; * Patients with early colorectal cancer confirmed by histopathology; * Patients who underwent endoscopic resection (including EMR, ESD, or equivalent techniques); * Pathological diagnosis indicating non-curative resection, defined by the presence of at least one of the following: positive resection margin, submucosal invasion depth \>1000 μm, poor differentiation, lymphovascular invasion, perineural invasion, or high-grade tumor budding; * Availability of complete clinicopathological and follow-up data; * Patients managed with either additional surgery or surveillance after endoscopic resection. Exclusion Criteria: * Patients with synchronous advanced colorectal cancer or distant metastasis at baseline; * History of other active malignancies; * Patients with inflammatory bowel disease, familial adenomatous polyposis, or other hereditary colorectal cancer syndromes; * Patients who received neoadjuvant therapy before endoscopic resection; * Incomplete pathological data or missing key variables; * Loss to follow-up or follow-up duration less than 6 months.