Vascular endothelial growth factor in pleural fluid for differential diagnosis of benign and malignant origin and its clinical applications

Our goal was to determine the role of vascular endothelial growth factor (VEGF) in diagnosing of pleural effusion (PE) in order to select patients deserving of more aggressive procedures. Seventy-nine consecutive patients with undiagnosed unilateral PE were enrolled. Pleural VEGF levels, measured using enzyme-linked immunosorbent assay (ELISA), were correlated to etiology of PEs and other markers (protein, lactic dehydrogenase, amylase, glucose). The median level of VEGF in exudates (n=65) was significantly higher than that in transudates (P=0.0001) and among exudates, it was significantly higher in malignant (n=49) than that in benign exudates (P=0.005). No significant differences were observed between malignant effusions due to lung cancer (n=11) and other malignant effusions [mesothelioma (n=13) and/or extra-thoracic cancer]. Among all variables evaluated, logistic regression found that only VEGF was significantly correlated with the presence of malignant disease (P=0.002). Analysis of the receiver operating characterists (ROC) curves showed that the areas under the curve of VEGF were significantly larger than that of amylase (P=0.02), glucose (P=0.01), lactic dehydrogenase (P=0.001) and protein (P=0.01). VEGF increased the diagnostic rate of cytological examination by 24%. VEGF may represent a helpful adjunct to conventional diagnostic tools in ruling out malignancy as a probable diagnosis, thus guiding the selection of patients who might benefit from further invasive procedures.