Pleural effusion is a common diagnostic problem. The analysis of serum and body fluids for
tumor markers has been intensively applied to clinical diagnosis. The aim of the present study was to determine the usefulness of simultaneous quantification of
carbohydrate antigen 19.9,
carbohydrate antigen 125,
neuron specific enolase,
mucinous-carcinoma-associated antigen, and
ferritin in samples of pleural fluids in the malign
pleural effusion and its differentiation from benign effusions. A total of 61
pleural effusions were collected from the patients, who were subjected either to simple needle aspiration or to tube drainage for the diagnosis of
pleural effusion.
Tumor markers were determined in benign patient groups with nonspecific
pleurisy, tuberculous pleurisy,
empyema,
congestive heart failure and in
malignancy groups consisting of
adenocarcinoma,
small cell lung carcinoma,
mesothelioma, epidermoid
lung cancer. The
tumor markers CA-19.9, CA-125, NSE, and
ferritin levels were quantified by the sandwich assay using the
streptavidin technology of ELISA in an ES-300 Boehringer-Mannheim analyser. MCA was measured by employing a two-side solid phase EIA method. MCA measurements were done by the Cobas-Core. For all patients, the effusions correctly or incorrectly identified by the different procedures as being malignant or nonmalignant are defined as true positive, false positive, true negative, and false negative, the term 'positive' referring to histologically proven
malignant pleural effusion while nonmalignant effusions are referred to as 'negative'. Therefore, sensitivity, specificity, positive predictive value, and negative predictive value were defined as diagnostic parameters. The cut-off values calculated were 352 U/ml for CA-125, 54 U/ml for CA-19.9, 555 for
ferritin, 11.1 for MCA and 8.7 for NSE. In our study, the highest sensitivity is found to be MCA with 100%; specificity, CA-19.9 with 97%; PPV, CA-19.9 and MCA with 95% and NPV, MCA with 100%. Our data imply that the co-measurement of MCA+CA-19.9+CA-125 levels may further improve their diagnostic value in
malignant pleural effusion compared with that of each tumour marker alone and may be useful in distinguishing malignant from benign
pleural effusions.