Study on Value of Carbohydrate Antigen 72-4 in Tumor Screening and Diagnosis / 胃肠病学

ABSTRACT

Background: Carbohydrate antigen 72-4 (CA72-4) is generally recognized as a tumor marker of digestive system. However, elevated serum CA72-4 level is also evident in many benign diseases and healthy subjects, and its sensitivity in diagnosing malignant tumor is quite poor. Aims: To reassess the value of CA72-4 in tumor screening and diagnosis. Methods: Three cohorts were established in this study. Inpatients who underwent a serum CA72-4 measurement and had a definite final diagnosis were included into Cohort 1 (retrospective study). Inpatients with elevated serum CA72-4 level who had not been diagnosed as malignant tumor before admission were included into Cohort 2 (retrospective study). Individuals who underwent a serum CA72-4 measurement and willing to take a follow-up for at least 2 years were included into Cohort 3 (prospective study). Malignancies had been preliminarily excluded in all individuals in Cohort 3 before enrollment. Results: Among the 2 173 patients recruited in Cohort 1, the prevalence of positive serum CA72-4 was significantly higher in patients with malignancies than those without (16.4% vs. 7.4%, P<0.05). The sensitivity and specificity of CA72-4 for diagnosis of malignant tumor were 36.5% and 76.2%, respectively, at the cut-off value (2.955 U/mL) identified by ROC curve analysis. Among the 1 807 patients recruited in Cohort 2, most of the participants (76.5%) did not have malignancies. Serum CA72-4 level was associated with the histological classification, tumor differentiation and TNM staging of malignancies (P<0.05). Among the 376 individuals who underwent a follow-up for no less than 2 years in Cohort 3, elevated serum CA72-4 level did not increase the risk of malignant tumor (OR=1.268, 95% CI 0.283-5.687). Conclusions: CA72-4 is not a sensitive marker for tumor screening, its value as an item in physical examination should be re-evaluated. In patients who had positive serum CA72-4 and malignant tumor was ruled out in initial examination, the necessity of long-term follow-up of serum CA72-4 needs to be discussed.