Background: The roles of tumor markers, such as carbohydrate antigen (CA) 125, CA 15-3, CA 19-9, and CYFRA 21-1 (a fragment of cytokeratin 19), in differentiating malignant pleural effusion (MPE) from benign effusions are not yet clear.
Methods: After a systematic review of English language studies, sensitivity, specificity, and other measures of accuracy of pleural concentrations of either 125, CA 15-3, CA 19-9, and CYFRA 21-1, or their combinations, in the diagnosis of MPE were pooled using random effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.
Results: Twenty-nine studies met our inclusion criteria for the analysis. The summary estimates of the sensitivity and specificity of these tumor markers were as follows: CA 125, 0.48/0.85; CA 15-3, 0.51/0.96; CA 19-9, 0.25/0.96; CYFRA 21-1, 0.55/0.91, for diagnosing MPE. The estimated summary receiver operating characteristic curves showed that the performance of pleural CA-125 and CA 19-9 measurement in the diagnosis of MPE was limited, whereas that of CA 15-3 and CYFRA 21-1 was better. When two or more of the above four tumor markers combined, or combined with carcinoembryonic antigen, the sensitivity and specificity were all increased at different extents.
Conclusions: The current evidences do not recommend using one tumor marker alone for the diagnosis of MPE, however, the combination of two or more tumor markers seems to be more sensitive. The results of tumor marker assays should be interpreted in parallel with clinical findings and the results of conventional tests.
- Pleural effusion
- Tumor marker