Diagnostic value of pleural cytology together with pleural CEA and VEGF in patients with NSCLC and lung metastases from breast cancer

Background: Pleural effusion (PE) is common in patients with advanced non-small cell lung cancer (NSCLC) and lung metastases from breast cancer, accounting for at least 20-30% of cases. Unfortunately, many patients with malignant PE exhibit a negative pleural cytology (PC), and thus further invasive diagnostic procedures, including VAT-guided biopsy, are required. The aim of this study was to evaluate the diagnostic value of PC together with pleural carcinoembryonic antigen (pCEA) and vascular endothelial growth factor (pVEGF) assay in cancer patients with PE. Methods: Thirty-six patients with suspicious PE scheduled to undergo VAT-guided biopsy underwent both PC and pCEA and pVEGF measurement before surgery. There were 20 (55.6%) males and 16 (44.4%) females, with an overall median age of 67 (range 40-82 years). Patients with non-diagnostic cytology were excluded from the study. pCEA was measured with automated method of immuno-chemiluminescence (LOCI, Dimension Vista, Siemens HD, Camberley, UK), while pVEGF with an enzyme-linked immunosorbent assay (ELISA) commercially available kit. According to previously obtained data from laboratory archival information, the optimum cutoff levels were 5 ng/mL and 6 ng/mL for pCEA and pVEGF, respectively. Results: Final pathology showed 10 (27.8%) patients with NSCLC, 13 (36.1%) with lung metastases, and 13 (36.1%) with benign PE. The age did not differ between groups (p=0.59). The sensitivity, specificity and accuracy of PC, and pleural CEA and VEGF are reported in the Table. The area under the curve (AUC) of the ROC curve of PC+pCEA+pVEGF in combination was 0.921 (95% CI: 0.513-0.973), and the diagnostic accuracy was 97.2%. Conclusions: In patients with PE, according to our results, the measurement of pleural CEA and VEGF, and PC evaluation together reached a very good accuracy and 100% specificity, and should be suggested in all cancer patients when a noninvasive evaluation of a PE is required as non-invasive procedure.