The diagnostic value of chest CT combined with serum CA242 and CYFRA21-1 for benign and malignant pulmonary nodules

Wei Jiao; Zhang Xin; Hua Zhengfeng; Dai Jin'e; Yang Yinhua; Liu Yijun; Cheng Youhua

doi:10.3969/j.issn.1671-6450.2025.11.004

Abstract：Objective To explore the diagnostic value of chest CT combined with serum carbohydrate antigen 242(CA242)and cytokeratin 19 fragment(CYFRA21-1)for benign and malignant pulmonary nodules.Methods From January 2023 to December 2024,98 patients with malignant pulmonary nodules(lung cancer)admitted to the Department of Respirato-ry and Critical Care Medicine of the 920th Hospital of the Joint Logistics Support Force were retrospectively selected as the lung cancer group,while 76 patients with benign pulmonary nodules admitted during the same period were selected as the be-nign nodule group.Enzyme-linked immunosorbent assay(ELISA)was used to detect serum CA242 and CYFRA21-1 levels.Kappa analysis was used to evaluate the consistency between chest CT alone and in combination with serum CA242 and CY-FRA21-1 for diagnosing benign and malignant pulmonary nodules compared with pathological diagnosis.Receiver operating characteristic curve(ROC)analysis was used to assess the diagnostic value of chest CT and serum CA242 and CYFRA21-1 for benign and malignant pulmonary nodules.Results Serum levels of CA242 and CYFRA21-1 in the lung cancer group were higher than those in the benign nodule group(t/P=8.194/＜0.001,8.326/＜0.001).The proportion of patients with larger nodule diameter,spiculation sign,vacuolar sign,and pleural indentation sign in the lung cancer group was higher than that in the benign nodule group(t/x2/P=17.422/＜0.001,14.456/＜0.001,19.531/＜0.001,18.316/＜0.001).The Kappa values for chest CT alone and in combination with serum CA242 and CYFRA21-1 for diagnosing benign and malignant pulmonary nodules were 0.738 and 0.884,respectively,indicating high and excellent consistency with pathological diagnosis(P＜0.01).The area under the curve(AUC)for chest CT,serum CA242,CYFRA21-1 alone,and their combination in diagnosing benign and ma-lignant pulmonary nodules were 0.863,0.837,0.842,and 0.943,respectively.The AUC of the combined diagnosis of all three was higher than that of each individual method(Z/P=2.169/0.030,2.873/0.004,2.801/0.005).Conclusion Chest CT combined with serum CA242 and CYFRA21-1 can significantly improve the diagnostic accuracy for benign and malignant pulmonary nodules,which is beneficial for early screening of lung cancer.