CEACAM5 and colonic neoplasm: Multiple studies have demonstrated the usefulness of preoperative CEA for predicting the prognosis of colon cancer patients (3–5), while other studies have suggested that postoperative CEA performed better than preoperative CEA in prognostic stratification; moreover, the recurrence-free survival of patients with an elevated preoperative CEA level but a normalized postoperative CEA level was not significantly different from that of patients with a normal preoperative CEA (6).