Survival in Resected Stage II Colorectal Cancer Is Dependent on Tumor Depth, Vascular Invasion, Postoperative CEA Level, and The Number of Examined Lymph Nodes

BACKGROUND: The aim of the present study was to determine which aspects of tumor histology influence postoperative early relapse and overall survival rates after radical resection of stage II colorectal cancer (CRC). METHODS: Data were collected for 425 patients with stage II CRC who began treatment at a single institution between January 2006 and October 2013. All the enrolled patients were followed up on until death or until December 2014. Clinically significant factors affecting postoperative early relapse and overall survival rates were analyzed. RESULTS: Using a multivariate analysis, tumor invasion depth (P = 0.008), vascular invasion (P = 0.029), postoperative carcinoembryonic antigen (CEA) level (P = 0.001), and retrieval of less than 12 lymph nodes (P = 0.002) were found to be independent predictors for postoperative early relapse. A combination of tumor invasion depth, vascular invasion, postoperative CEA level, and number of lymph nodes retrieved showed that the greater the number of predictors involved, the higher the likelihood of postoperative early relapse and the poorer the overall survival. CONCLUSIONS: This study revealed that T4 invasion, vascular invasion, postoperative CEA level, and the number of examined lymph nodes may significantly affect the prognosis of stage II CRC patients after radical resection. The risks of postoperative early relapse and worse clinical outcome increase in proportion to the values of these four parameters.