Evaluation of the diagnosis value of carcinoembryonic antigen in malignant pleural effusion

Abstract

Objective: To investigate the diagnostic value of serum and pleural fluid carcinoembryonic antigen (CEA) for malignant pleural effusion (MPE). Methods: The concentration of CEA in serum and pleural fluid of 286 patients with the diagnosis confirmed by pleural biopsy through medical thoracoscopy were retrospectively analyzed. MPE was confirmed in 171 cases which were divided into two groups (adenocarcinoma group with 121cases and non-adenocarcinoma group with 50 cases) and benign pleural effusion in 115 cases. The optimal cutoff for MPE and MPE caused by adenocarcinoma were determined by using the ROC curve. Results: The concentration of serum CEA 12.27(3.80, 58.45) μg/L was significantly higher in MPE caused by adenocarcinoma than that of non-adenocarcinoma 1.91(1.08, 4.55) μg/L and benign effusion 1.32(0.86, 2.27) μg/L (both P<0.001), but there was no statistically significant difference between benign and non-adenocarcinoma effusion (P=0.728). The concentration of pleural fluid CEA 160.70(30.48, 1 000.00) μg/L was significantly higher in MPE caused by adenocarcinoma than that of non-adenocarcinoma 1.77(0.51, 11.39) μg/L and benign effusion 1.09(0.60, 1.68) μg/L (both P<0.001), and higher in non-adenocarcinoma effusion than that of benign effusion (P<0.05). The cutoff value of serum and pleural fluid CEA for MPE was 3.10 and 5.83 μg/L, the sensitivity respectively was 67.3% and 74.3%, the specificity respectively was 87.8% and 98.3%, positive predictive value respectively was 89.2% and 98.5%, negative predictive value respectively was 64.3% and 72.0%. The cutoff value of serum and pleural fluid CEA for MPE caused by adenocarcinoma was 3.54 and 7.30 μg/L, the sensitivity respectively was 76.0% and 91.7%, the specificity respectively was 74.0% and 72.0%, positive predictive value respectively was 87.6% and 88.8%, negative predictive value respectively was 56.1% and 78.3%. Conclusions: The concentration of serum and pleural fluid CEA have diagnostic significance to MPE, especially MPE caused by adenocarcinoma. The diagnostic value of pleural fluid CEA is superior to serum CEA.