Distribution and Analysis of Metastatic Lymph Nodes in Colorectal Cancer Patients (DIAMOND)

Inclusion Criteria: * Aged between 18 and 80 years * Pathologically confirmed adenocarcinoma of the colon or rectum * Underwent radical resection for colorectal cancer with a D3 lymphadenectomy and lymph nodes were submitted for pathological examination according to standardized station-based and distance-based protocol * No distant metastasis or distant metastasis within 6 months after surgery * No history of other malignant tumors or severe systemic diseases * No immune diseases or inflammatory bowel diseases * Non-emergency surgery * With complete clinicopathological and follow-up data Exclusion Criteria: * Pathologically confirmed benign tumors or non-adenocarcinoma malignancies * Underwent local excision or palliative resection * Regional lymph nodes were not dissected or submitted for pathological examination according to the unified station-based or distance-based protocol * With distant metastasis or distant metastasis within 6 months after surgery * Dual or multiple primary colorectal cancers or concurrent other malignant tumors * Had a previous diagnosis of immune diseases or inflammatory bowel disease such as ulcerative colitis or Crohn's disease * Underwent emergency surgery * Had incomplete clinicopathological or follow-up data