Diagnostic value of tumor markers assays in benign and malignant pleural effusions

Abstract

Objective To evaluate the diagnostic value of four common pleural fluid tumor markers.Methods A total of 126 patients (52 with definite malignant effusions, and 74 with benign effusions) were enrolled. Tumor markers [carcinoembryonic antigen (CEA), cancer antigen 125(CA125), carbohydrate antigen 15-3 (CA 15-3) and cytokeratin 19 fragments (CYFRA21-1)] in pleural fluid were determined by electrochemiluminescence immunoassay. The sensitivities, specificities, accuracies and youden index(YI) of single and combination of those markers were calculated. Results Malignant pleural effusions had higher levels of pleural fluid markers than effusions due to benign conditions. CA125 had the highest sensitivity (90.4 %), and CYFRA21-1 had the highest specificity (79.7 %), CEA and CYFRA21-1 had the highest accuracy (71.4 %), CEA had the highest YI (0.41). The combination of several serum tumor markers had higher sensitivities than the single marker for diagnosis of malignant pleural effusion. When the three tumor markers were combined with CEA, the combination of CEA, CYFRA21-1 and CA15-3 yielded the best results,with a sensitivity of 92.3 %, a specificity of 78.4 %, and an accuracy of 84.1%, YI of 0.71, while the combination of four tumor markers had a sensitivity of 94.2 %, a specificity of 75.7 %, and an accuracy of 83.3 %, YI of 0.70, and there was no statistical significance between the two combinations (P ＞0.05).Conclusion Single tumor marker had limited diagnostic value for malignant pleural effusions, while CEA,CYFRA21-1 and CA15-3 yielded the best and the most economic method, that guiding the selection of patients who might benefit from further invasive procedures. Key words: Pleural effusion; Tumor markers, biological; CEA; CA125; CA15-3; CYFRA21-1