Background and Aims According to the Chinese Guidelines for the Diagnosis and Treatment of Colorectal Cancer (2023 Edition), patients with early-stage colorectal cancer who present with high-risk factors require additional radical surgery following endoscopic resection. However, due to the relatively low rate of lymph node metastasis in early colorectal cancer, some patients may not benefit from such supplemental surgery. Therefore, accurately identifying patients who are truly likely to benefit and refining the indications for supplemental surgery are pressing clinical challenges. This study was conducted to investigate the risk factors and distribution patterns of lymph node metastasis following additional radical surgery through retrospectively analyzing a large single-center cohort, thereby providing evidence-based support for clinical decision-making.Methods Clinicopathologic data were retrospectively reviewed for patients with early-stage colorectal cancer who underwent additional radical surgery at Fudan University Shanghai Cancer Center between 2008 and 2023. Binary Logistic regression and multivariate analyses were performed to identify risk factors associated with lymph node metastasis, and the distribution characteristics of metastatic lymph nodes were further examined.Results A total of 417 patients were included in the study, with lymph node metastasis confirmed in 36 cases (8.63%) postoperatively. Over time, the number of patients undergoing supplemental surgery increased, while the proportion of cases with residual cancer decreased. Among 243 patients included in the risk factor analysis, univariate analysis indicated that submucosal invasion depth of SM2 or greater, poor tumor differentiation, positive vascular invasion, and tumor location were high-risk factors for lymph node metastasis. Multivariate analysis identified invasion depth (P=0.039) and tumor location (P=0.014) as independent risk factors. Among the metastatic cases, 58.3% involved a single lymph node; 63.9% of metastases were limited to the first station, and 36.1% extended to the second station, with no metastasis found at the third station. Only four patients had preoperative imaging suggestive of lymph node enlargement.Conclusion Although the number of supplemental surgeries following endoscopic resection of early-stage colorectal cancer has increased significantly, the actual rate of lymph node metastasis remains low, suggesting a potential risk of overtreatment. Submucosal invasion depth ≥SM2 and tumor location are independent risk factors for metastasis. D₂ lymph node dissection is deemed necessary, while the diagnostic value of imaging remains limited. Clinical decisions should prioritize precision and individualized treatment planning.