Evaluation of two strategies for the interpretation of tumour markers in pleural effusions.

BACKGROUND: Pleural effusions present a diagnostic challenge. Approximately 20% are associated with cancer and some 50% require invasive procedures to perform diagnosis. Determination of tumour markers may help to identify patients with malignant effusions. Two strategies are used to obtain high specificity in the differential diagnosis of malignant pleural effusions: a) high cut-off, and b) fluid/serum (F/S) ratio and low cut-off. The aim of this study is to compare these two strategies and to establish whether the identification of possible false positives using benign biomarkers - ADA, CRP and % of polymorphonuclear cells - improves diagnostic accuracy. METHODS: We studied 402 pleural effusions, 122 of them malignant. Benign biomarkers were determined in pleural fluid, and CEA, CA72-4, CA19-9 and CA15-3 in pleural fluid and serum. RESULTS: Establishing a cut-off value for each TM for a specificity of 100%, a joint sensitivity of 66.5% was obtained. With the F/S strategy and low cut-off points, sensitivity was 77% and specificity 98.2%, Subclassifying cases with negative benign biomarkers, both strategies achieved a specificity of 100%; sensitivity was 69.9% for single determination and 80.6% for F/S ratio. CONCLUSIONS: The best interpretation of TM in the differential diagnosis of malignant pleural effusions is obtained using the F/S ratio in the group with negative benign biomarkers.

Diagnostic Accuracy of Tumor Markers CYFRA21-1 and CA125 in the Differential Diagnosis of Ascites.

BACKGROUND: The usefulness of tumor markers in the differential diagnosis of cancer in patients with ascites remains a matter of controversy. Few studies have reported the measurement of cancer antigen 125 (CA125) and cytokeratin 19 soluble fragments (CYFRA21-1) in ascitic fluid. The aim of the present study was to evaluate the diagnostic accuracy of these tumor markers in the detection of malignant ascites. MATERIALS AND METHODS: We analyzed CA125 and CYFRA21-1 from 143 consecutive undiagnosed patients with ascitis. RESULTS: Use of CA125 gave a sensitivity of 39.7% and a specificity of 98.8%, and CYFRA21-1 a sensitivity of 50.0% and a specificity of 97.6% in differential diagnosis of malignant ascites. For combined use of CA125 plus CYFRA21-1, sensitivity was 65.5% and specificity 96.5%. In patients with negative cytology, these two tumor markers had a sensitivity of 50% and a specificity of 96.5%. CONCLUSION: The determination of tumor markers in ascitic fluid could be useful for the diagnostic assessment of patients with ascites.