After the model selection, eight independent prognostic factors for RFS were identified, including chronic kidney disease (HR = 1.53), preoperative CEA level (on base-10 logarithmic scale, HR = 1.73), cancer stage (II vs. I, HR = 2.78; III vs. I, HR = 6.77), perioperative pRBC transfusion (HR = 1.39), pathologic lymphovascular invasion (HR = 1.37) and perineural invasion (HR = 1.68), preoperative chemotherapy and/or radiotherapy (HR = 2.46), and postoperative radiotherapy (HR = 1.95) (Table 3). Here, CEACAM5 is linked to chronic kidney disease.