With regard to other clinicopathological variables, age (P < 0.001), hypoalbuminemia (P = 0.002), anemia (P = 0.036), elevated preoperative CEA (P < 0.001), elevated preoperative CA19-9 (P < 0.001), clinical T stage (P < 0.001), differentiation (P < 0.001), histopathology (P = 0.037), peritoneal metastasis (P < 0.001), multiple metastasis (P < 0.001), pathological T stage (P = 0.001), pathological N stage (P = 0.003), post-operative complication (P = 0.012), and post-operative chemotherapy (P < 0.001) were all associated with the prognosis in metastatic CRC patients receiving PTR (Table 2). Here, CEACAM5 is linked to anemia.