Diagnostic utility of CYFRA 21-1, carcinoembryonic antigen, CA 125, neuronspecific enolase, and squamous cell antigen level determinations in the serum and pleural fluid of patients with pleural effusions

BACKGROUND. To the authors' knowledge the role of tumor marker determinatio n in the differential diagnosis of pleural effusions has not been establish ed definitively. The current article reports the results of a study of CYFR A 21-1, carcinoembryonic antigen (CEA), cancer antigen 125 (CA 125), squamo us cell antigen (SCC), and neuron specific enolase (NSE) in the serum and p leural fluid of patients with pleural effusions of diverse etiologies. METHODS. One hundred forty-six patients with pleural effusions [43 malignan t, 47 tuberculous, 32 miscellaneous benign, and 24 paramalignant) were stud ied prospectively. Levels of CYFRA 21-1, CA 125, CEA, NSE, and SCC were mea sured by radioimmunoassay in the pleural fluid in all patients and in the s erum in 118 patients. RESULTS. There were no significant differences between the serum and pleura l fluid levels of tumor markers with the exception of CA 125, which was hig her in the pleural fluid. With maximum specificity, the highest sensitivity in the diagnosis of pleural malignancy was obtained with a combination of CYFRA 21-1 with a cutoff value of 150 U/L), CEA (with a cutoff value of 40 ng/mL), and CA 125 with a cutoff value of 1000 ng/mL) in pleural fluid. NSE and SCC added no diagnostic value. The simultaneous use of tumor markers a nd cytology in pleural fluid increased the sensitivity from 55.8% to 81%. CONCLUSIONS. These findings suggest that a combination of CYFRA 21-1, CEA, and CA 125 in the pleural fluid can be a useful addition to pleural cytolog y in the diagnosis of malignant pleural effusion. (C) 1999 American Cancer Society.