Clinical value of combined detection of tumor markers in effusion fluid for diagnosis of malignant pleural effusion and ascites

Objective: To study the clinical usefulness of combined detection of tumor markers in effusion fluid in patients with malignant pleural effusion or ascites. Methods: Combined detection of six tumor markers (CA125, CA50, CA15-3, CYFRA21-1, βHCG, HCG) in effusion fluid was performed in 92 patients with malignant pleural effusion and 78 patients with malignant ascites as well as 100 control benign specimens. These tumor markers were examined with CLIA, except CA50, which was examined with RIA. Exfoliative cytology was also examined in the malignant specimens. Results: The positive rate of these markers was highest with CA125, followed by CA50, CA15-3, CYFRA21-1, βHCG and HCG in order. βHCG and HCG, though with quite low positive rate, were still useful markers due to the almost zero false-positive rate, i.e. very high specificity. For combined determination of two markers, CA15 + CYFRA21-1 or CA125 + CA50 would result in the highest positive rate. For highly suspected but undetermined cases, the following criteria for malignancy would be helpful: (1) two or more positive among CA125, CA50, CA15-3, CYFRA21-1 (2) One of the four CAs positive + either βHCG or HCG (3) Both βHCG and HCG positive. Tumor markers positiveness would be supplementary to doubtful cytological studies. Conclusion: Combined detection of tumor markers in effusion fluid would be very helpful for diagnosis of malignancy. (authors)