[Tumor markers in pleural effusion of patients with lung cancer and patients with tuberculous pleurisy].

Carcinoembryonic antigen (CEA), cancer antigen 125 (CA 125), NCC-ST-439, carbohydrate antigen 19-9 (CA 19-9), cytokeratin 19 fragment (CYFRA 21-1), sialyl Lewis X-i antigen (SLX), progastrin-releasing peptide (ProGRP), squamous cell carcinoma antigen (SCC) and neuron specific enolase (NSE) were evaluated in the pleural effusion of 39 patients with lung cancer (29 adenocarcinomas, seven small-cell carcinomas, three squamous cell carcinomas) and 43 patients with tuberculous pleurisy. The levels of the tumor markers other than SCC and NSE were significantly higher in lung cancer than in tuberculosis. High levels of CYFRA 21-1 and SCC were observed in squamous cell carcinoma and high levels of ProGRP and NSE were observed in small-cell carcinoma. According to the validity score, sensitivity (%) + specificity (%) - 100, the optimal cut-off levels of pleural effusion were 8.1 ng/ml for CEA, 660 U/ml for CA 125, 2.6 U/ml for NCC-ST-439, 10 U/ml for CA 19-9, 65 ng/ml for CYFRA 21-1, 140 U/ml for SLX, 23.2 pg/ml for ProGRP, 0.6 ng/ml for SCC and 5 ng/ml for NSE. By comparison of validity scores for each optimal cut-off level and of receiver operating characteristic (ROC) curves, we suggest that a CEA assay is the most useful for pleural effusion. The combined assay of CEA + ProGRP and CEA + ProGRP + CYFRA 21-1 were considered to be useful.