Carcinoembryonic antigen assay in pleural effusions

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.

Serum-based protein biomarkers for detection of lung cancer

Lung cancer is one of the most common cancers in terms of both incidence and mortality.The major reasons for the increasing number of deaths from lung cancer are late detection and lack of effective therapies. To improve our understanding of lung cancer biology, there is urgent need for blood-based, non-invasive molecular tests to assist in its detection in a cost-effective manner at an early stage when curative interventions are still possible. Recent advances in proteomic technology have provided extensive, high throughput analytical tools for identification, characterization and functional studies of proteomes. Changes in protein expression patterns in response to stimuli can serve as indicators or biomarkers of biological and pathological processes as well as physiological and pharmacological responses to drug treatment, thus aiding in early diagnosis and prognosis of disease. However, only a few biomarkers have been approved by the FDA to date for screening and diagnostic purposes. This review provides a brief overview of currently available proteomic techniques, their applications and limitations and the current state of knowledge about important serum biomarkers in lung cancer and their potential value as prognostic and diagnostic tools.

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.

Combined effusion fluid tumor marker assay, carcinoembryonic antigen (CEA) and human chorionic gonadotropin (hCG), in the detection of malignant tumors

Carcinoembryonic antigen (CEA) and human chorionic gonadotropin (hCG) and protein concentrations were determined on 81 random pleural and ascitic effusions submitted for cytologic examination. CEA and hCG assay results were expressed as direct concentrations and with respect to total protein concentration. Levels of significance for malignant fluids were established as follows: CEA greater than or equal to 10 ng/ml, hCG greater than or equal to 10 mIU/ml, CEA greater than 500 ng/g protein, hCG greater than or equal to 500 mIU/g protein. Clinical follow-up demonstrated 55 fluids associated with coexisting malignant tumors and 26 fluids not associated with malignancies. This study suggests effusion fluid CEA and hCG assay may provide a useful adjunct to cytology in the evaluation of effusion fluids for malignancy. Assay results, furthermore, may be more accurately expressed with respect to effusion protein concentration.

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.