Evaluation of Cytokeratin 19 Fragment (CYFRA 21-1) as a Tumor Marker in Malignant Pleural Effusion

fragment) asa tumormarkerinpleural effusion andevaluate the valueof combining CYFRA 21-1 andcarcinoembryonic antigen (CEA) assays asa diagnostic aid in the malignant pleural effusion. Methods: One hundred and twenty-six patients (72 malignant and 54 benign pleural effusion) were included in this retrospective study. The effusion levels of CYFRA 21-1 and CEA were measured using radioimmunometric assay. Results: The median valuesof CYFRA 21-1 in benign andmalignant pleural effusion are 15 and 70 ng/ml, respectively. Using a cut-offvalueof 50 ng/ml, defined at 94 % specificity, thediagnostic sensitivity of CYFRA 21-1 for non-small cell lungcarcinoma (n =61), squamous cell carcinoma (n =21), adenocarcinoma (n =40) and small cell lung cancer (n =11) was 64, 71, 60 and 18%, respectively. Regardless of cell types, the diagnostic sensitivity of CYFRA 21-1 and CEA in malignant pleural effusion (n=72) was57 and60%, respectively (cut-off valueof 10 ng/ml inCEA assay). Combining CEA with CYFRA 21-1, the diagnostic sensitivity may increase up to 72%, whichwas definedat 89 % specificity. Conclusion: CYFRA21-1 assay may be a useful tumor marker for discriminating benign from malignant pleural effusion, especially in those of non-small cell lung cancer. The combined use of CEA and CYFRA 21-1 assay in the malignant effusion may increase the diagnostic yield compared with CEA or CYFRA21-1 alone. Key words: cytokeratin- CYFRA 21-1- tumormarker- pleuraleffusio