Clinical Significance of Carcinoembryonic Antigen and Carbohydrate Antigen 19-9 in the Differential Diagnosis of Benign and Malignant Pleural Effusion

Objective To study the clinical significance of determining carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9(CA19-9) in the differential diagnosis of benign and malignant pleural effusion. Methods Pleural effusion CEA and CA19-9 were determined in 172 patients with malignant pleural effusion and 149 patients with benign pleural effusion by ELISA method and their diagnostic sensitivity and specificity were analyzed. Results With CEA≥5 ng/ml,≥15 ng/ml ,≥20 ng/ml,≥30 ng/ml and ≥40 ng/ml in pleural effusion as positive judgment standard,their sensitivities were 59.88%,47.67%,46.51%,40.70%,38.37% and specificities were 86.58%,93.96%,94.63%,96.64%,98.66% respectively. With CA19-9≥37U/ml in pleural effusion as positive judgment standard,their sensitivity and specificity were 28.22% and 95.95%. Conclusion Determination of CEA and CA19-9 in pleural effusion plays an important role in the differential diagnosis of benign and malignant pleural effusion. When the level of CEA is ≥40 ng/ml or the level of CA19-9 in pleural effusion is ≥37U/m,the possibilities of malignant pleural effusion are 97.06% and 88.46% respectively.