Diagnostic value of CYFRA 21-1, CEA, and CA125 for bone metastasis of lung cancer

Objective: To evaluate the sensitivity, specificity, and accuracy of the serum tumor markers cytokeratin 19 fragment (CYFRA 21-1), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125) in the diagnosis of bone metastases in patients with lung cancer. Methodology: A total of 134 patients with lung cancer, diagnosed by pathological examination or bronchoscopic biopsy, as well as 105 healthy subjects, were enrolled in the study. The cancer patients were divided into a metastasis-negative group, a localized metastasis group (1 to 2 metastases), and an extensive metastasis group (3 or more metastases). Serum levels of CYFRA 21-1, CEA, and CA125 were measured in each subject. The diagnostic efficiency of three tumor markers, used alone or in combination, was assessed using ROC analysis and compared with that of X-ray, CT, and emission computed tomography (ECT). Results: The levels of CYFRA 21-1, CEA, and CA125 were highest in patients with extensive metastasis, and lowest in patients without metastasis. The optimal cutoff value of CYFRA 21-1, CEA, and CA125 for diagnosing bone metastasis of lung cancer was 42.59 ng/ml (AUC: 0.908), 36.35 ng/ml (AUC: 0.854) and 36.21 U/ml (AUC: 0.786), respectively. The combined use of CYFRA 21-1, CEA, and CA125 was more sensitive than X-ray and more specific than CT. Conclusions: Combined determination of CYFRA 21-1, CEA, and CA125 can significantly improve accuracy and positive rates of diagnosis of bone metastasis in patients with lung cancer. Compared with imaging methods, serological detection is simple, rapid, and highly cost-effective. .