[Carcinoembryonic antigen (CEA) and CEA-like activities in ascites and pleura-effusions (author's transl)]

Diagnostic Value of Carcinoembryonic Antigen (CEA) Assay in Pleural Effusions

Carcinoembryonic antigen (CEA) levels were evaluated by a direct radioimmunoassay in the effusion fluids and plasma samples from 107 patients with pleural effusions of unknown etiology. CEA levels higher than 20 ng/ml were detected in 55 % of pleural effusions from patients with malignant disease: 40 % of the patients in this group had values of plasmatic CEA lower than 20 ng/ml. With the only exception of 4 patients with empyema, CEA levels were uniformly lower than 20 ng/ml in the effusion fluid of patients with benign disease. Moreover, CEA levels higher than 20 ng/ml were observed in 81.2 % of pleural effusions and 31.2 % of plasma samples from patients with cytology positive for malignancy, whereas increased CEA levels were observed in 37.5 % of effusion fluids and 33.3 % of plasma samples from patients with malignant disease but negative cytology in the pleural effusion. CEA assay in the effusion fluid represents a useful tool of high specificity and good sensitivity to discriminate between benign and malignant etiology of pleural effusions.

Ascitic fluid analysis for the differentiation of malignancy-related and nonmalignant ascites. Proposal of a diagnostic sequence

The authors tried to differentiate malignancy-related from nonmalignant ascites with a sequence of sensitive followed by specific ascitic-fluid parameters. There were four results of this study. First, of nine parameters investigated in a first series of 48 patients, 28 with nonmalignant and 20 with malignancy-related ascites, ascitic-fluid cholesterol and fibronectin yielded the best negative predictive value of 92% each. Carcinoembryonic antigen (CEA) and cytologic examination both showed a positive predictive value of 100%. Second, combining cytologic examination (sensitivity, 70%) and CEA determination (sensitivity, 45%) increased the sensitivity to 80%. Third, cytologic findings were negative in all ascitic-fluid samples with a cholesterol concentration below the cutoff value of 45 mg/100 ml. Fourth, based on the results of the first series of 48 patients, the diagnostic sequence with cholesterol as a sensitive parameter, followed by the combination of cytologic examination and CEA determination as specific parameters, was tested in a second series of 71 patients, 37 with nonmalignant and 34 with malignancy-related ascites. Again cytologic examination was negative in all samples with cholesterol levels below 45 mg/100 ml. In the total of 119 patients, this diagnostic sequence did not identify 9% of patients with malignancy-related ascites, and 82% of samples classified as malignancy related by cholesterol levels above 45 mg/100 ml were confirmed by positive cytologic examination and/or CEA level above 2.5 ng/ml. Thus, a diagnostic sequence with ascitic-fluid cholesterol determination, followed by cytologic examination and CEA determination, in samples with cholesterol levels above 45 mg/100 ml should permit a cost-efficient routine differentiation of malignancy-related from nonmalignant ascites.

Ascitic fluid concentrations of fibronectin and cholesterol: comparison of differential diagnostic value with the conventional protein determination

Ascitic fluid concentrations of fibronectin, cholesterol and protein were determined in 95 patients: 38 with cirrhosis of the liver, 10 with miscellaneous nonmalignant diseases, 43 with peritoneal carcinomatosis and 4 with liver metastases or hepatocellular carcinoma. Fibronectin, cholesterol and protein at discrimination values of 7.5 mg/100 ml, 45 mg/100 ml and 3.0 g/100 ml, respectively, separated patients with peritoneal carcinomatosis from patients with cirrhosis with an efficiency of 94%, 90% and 85%, respectively. Thus, ascitic fluid determinations of fibronectin and cholesterol offer good discrimination of cirrhotic ascites from ascites related to peritoneal carcinomatosis, superior to the conventional protein determination. However, the failure of all parameters to distinguish ascites caused by miscellaneous nonmalignant diseases from malignancy-related ascites underscores the importance of highly specific methods to confirm a suspected diagnosis of malignancy-related ascites.

Value of ascitic lipids in the differentiation between cirrhotic and malignant ascites

Ascitic fluid concentrations of cholesterol, triglycerides and phospholipids, were compared with ascitic fluid total protein in 40 patients with chronic liver disease, 51 patients with various neoplasms and 1 patient with cardiac failure. Seven patients with both chronic liver disease and malignancy were considered separately. The first 54 patients (23 cirrhotic and 31 with malignancy) were used to determine median values and ranges and to define the most suitable cutoff concentrations between both groups. Median values for cholesterol (75 mg per dl), phospholipids 0.79 mmole per liter), triglycerides (75 mg per dl) and protein (3.8 gm per dl) were higher in malignant ascites compared to ascitic fluid concentrations of cholesterol (20 mg per dl), phospholipids (0.33 mmole per liter), triglycerides (51 mg per dl) and protein (1.9 gm per dl) in patients with cirrhosis. The best discrimination values were 48 mg per dl for cholesterol, 0.6 mmole per liter for phospholipids, 65 mg per dl for triglycerides and 2.5 gm per dl for protein. Application of these cutoff points to 38 subsequent patients (17 cirrhotic, 1 with cardiac failure and 20 with malignancy) revealed an efficiency of 86.8% for cholesterol, 86.8% for phospholipids, 68.4% for triglycerides and 79.0% for protein. From the data of all 92 patients, an efficiency of 92.3% for cholesterol, 79.4% for phospholipids, 72.8% for triglycerides and 79.4% for protein was calculated. We conclude that ascitic fluid cholesterol determination offers an excellent, cost-effective discrimination of ascites due to cirrhosis vs. ascites caused by malignancies.

Carcinoembryonic antigen in pleural effusions. Diagnostic value in malignant mesothelioma

The usefulness of the determination of carcinoembryonic antigen (CEA) in pleural effusion was assessed as an aid to the diagnosis of malignant mesothelioma. The concentration of CEA was determined by radioimmunoassay (RIA) in pleural fluid of 213 adult patients, of which 140 had malignant pleural disease and 73 had nonmalignant pleural disease. Pleural fluid CEA (PF CEA) was lower than 12 ng/ml in all 15 mesotheliomas. The statistical probability of a mesothelioma associated with PF CEA greater than 15 ng/ml was found to be zero. The CEA assay in pleural effusion proved to be a valuable adjunct to other diagnostic procedures in differentiating the malignant mesothelioma from metastatic serosal spread.

Differential diagnosis of pleural effusions: clinical usefulness of cell marker quantitation

Carcinoembryonic antigen (CEA), orosomucoid beta 2 microglobulin, and alpha fetoprotein were quantified in the pleural fluid and serum of 58 hospitalized consecutive patients in order to differentiate malignant from non-malignant effusions. Cytologic examination of the effusions was also performed. The orosomucoid assay was the most helpful in identifying malignant effusions; higher values (greater than 100 mg/100 ml) were found in 74 percent (26/35) of malignant effusions. Quantitation of carcinoembryonic antigen had a high specificity (95 percent) but a low sensitivity (36 percent) for the detection of malignant pleural effusions. The parallel quantitation of CEA and orosomucoid had a higher sensitivity (86 percent) which increased when associated with cytologic examination. The sensitivity of cytology was only 46 percent. The concentrations of orosomucoid in pleural effusions correlated well with serum concentrations. Alpha fetoprotein and beta 2 microglobulin quantitations were of no clinical value for diagnosing malignant effusions. It is suggested the cytologic examination combined with orosomucoid and CEA quantitation in pleural fluid have a considerable clinical value for the diagnosis of pleural effusions.