Subgroup analyses based on the AJCC T and N stages for these patients (Table S2) showed that CEA still exhibited low AUCs (0.533 and 0.533 respectively) and sensitivity (7.3 and 7.3 per cent respectively), both in patients with advanced T stage and lymph node metastasis. Here, CEACAM5 is linked to metastatic malignant neoplasm in the lymph nodes.