CEACAM5 and neoplasm: As shown in Table 5, the age, maximum tumor diameter, pathological stage, and carcinoembryonic antigen (CEA) of the enrolled patients have no correlation with chemotherapy efficacy, but patients with abnormal CA19-9 achieved PR/SD = 0.015 after chemotherapy and PR/SD/PD = 0.018 after chemotherapy (P < 0.05).