삼출성 늑막액에서 양악성 감별지표로서 CEA; TPA; SCC Ag 측정의 의의

Abstract

Carcinoembryonic antigen(CEA), the most widely used tumor marker was measured in pleural fluid of patients with exudative pleural effusions in order to differentiate malignant from benign effusions. This study was performed to find out if there is any clinical utility in differential diagnosis of malignancy by measuring simultaneously CEA, tissue polypeptide antigen(TPA) and squamous cell carcinoma antigen(SCC Ag) in serum and pleural fluid. The study population was 61 patients with exudative pleural effusions who were admitted to Keimyung University Hospital from January 1 to August 31, 1997. Each CEA, TPA and SCC Ag level in serum and pleural fluid were measured using radioimmunoassay method. These patients were divided to malignant and benign group. Malignant group consists of 28 cases and benign group consists of 33 cases. And the sensitivity and specificity of each tumor marker was obtained using cut-off value and that combining tumor markers and pleural fluid cytology were also obtained and analyzed. When the cut-off value was applied to CEA and TPA in serum using 7.0 ng/ml and 80.0 ng/ml respectively, the highest sensitivity was obtained without specificity being lowered. The same result was obtained when the cut-off value was applied to CEA and TPA in pleural fluid using 5.0 ng/ml and 4700.0 ng/ml respectively. When CEA in pleural fluid or TPA in serum were measured in combining with pleural fluid cytology sensitivity was increased without decreasing specificity than measured in pleural fluid cytology alone. When CEA in serum and TPA in serum were measured in combining with pleural fluid cytology simultaneously, the highest sensitivity was produced without decreasing specificity than measured in any other combinations. In addition, when serum CEA and TPA in serum were measured in the negative group of pleural fluid cytology, high sensitivity and specificity were obtained. These data suggest that CEA and TPA can be used as useful tumor markers for the differential diagnosis of malignancy and benign condition in patients with exudative pleural effusions.