Diagnostic Utility Of Serum And Pleural Fluid Tumor Markers (Cyfra 21-1,CEA, NSE, SCC) In Patients With Pleural Effusions From Primary Lung Cancer

Study objective: To assess the diagnostic values of cytokeratin 19 fragments (CYFRA 21–1), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE) and squamous cell carcinoma antigen (SCC) as markers of pleurisy in primary lung cancer and as an aid in histological diagnosis.Design: Analysis of four tumor markers in serum and pleural fluid with a confirmatory diagnosis of malignancy by pleural cytology or material obtained during bronchoscopy.Setting: The First Affiliated Hospital of Chongqing Medical University, Department of PulmonologyPatients and Methods: Data was collected from the case sheets of patients admitted in hospital with a preliminary diagnosis of pleural effusion during the period of January 2010 to July 2010. A total of 37 patients with malignant effusions and 23 patients with benign effusions were enrolled. Levels of CEA, CYFRA 21–1, NSE, and SCC were measured in the serum and pleural fluid of these patients.Results: Patients with lung cancer were found to have significantly higher levels of CEA, CYFRA 21–1, NSE and SCC than those in the benign group. The serum tumor marker with the highest sensitivity for malignancy was CYFRA 21–1 (86.49%), whereas serum NSE had the highest specificity (95.65%).In pleural fluid, CYFRA 21-1 had the highest sensitivity (97.3%),whereas CEA had the highest specificity (91.3%) and accuracy of 83.33%. When combinations of tumor markers were evaluated, CEA and CYFRA 21-1 gave a high diagnostic performance in both serum and pleural fluid. Moreover, the sensitivity of all the studied markers was relatively higher in pleural fluid than in serum. The use of these biomarkers could also suggest the histological diagnosis in the malignant group: CEA in adenocarcinoma, SCC in squamous cell carcinoma and NSE in SCLC.Conclusions: In our study, significant differences between the serum and pleural fluid samples, as well as between the malignant and benign forms of pleural effusion were noted. CYFRA 21-1 proved to be the single and most sensitive tumor marker and its combination with CEA could enhance its diagnostic yield. SCC and NSE can be considered as useful parameters in the screening of squamous cell carcinoma and SCLC respectively. In our study, the use of our tumor marker panel has shown a clear relationship with histological subtype.