RESUMO
We evaluated the diagnostic utility of the carcinoembryonic antigen (CEA), neuron-specific enolase (NSE) and squamous cell carcinoma antigen (SCC Ag.) in malignant pleural effusion (MPE). CEA, NSE and SCC Ag, blood and pleural levels were quantified by enzyme immunoassay (EIA) in 85 patients with pleural effusions: 35 non malignant pleural effusions, and 50 MPE; 42 with lung carcinoma (LC), and 8 with extrapulmonary carcinoma. The sensitivity and specificity was compared to cytological results of the pleural fluid. The sensitivities of CEA7 NSE and SCC Ag. (in pleural fluid) were 59.5%, 48.7% and 16.7% respectively in patients with LC (specificity higher than 90%). Using a combination with CEA and NSE, the sensitivity reached 80.9% (specificity, 91.4%). The cytology of pleural fluid was positive in 45.2%. The pleural/blood ratios did not improve the diagnostic performance. In patients with extrapulmonary carcinoma, the sensitivity of these tumor markers was lower. The combination of CEA and NSE pleural levels is useful in the diagnostic approach to the patient with pleural effusion. A high level of NSE is suggestive of small cell lung cancer (SCLC).
