Validation of Selected Tumor Markers in Differentiation Between Malignant and Benign Serous Effusion

Abstract

This is a descriptive study carried out in Khartoum State hospitals during the period from October 2008 to April 2011. The study aimed to validate the use of some tumor markers (EMA, CA15-3, CEA, and NSE) in the differential diagnosis between benign and malignant serous effusion. One hundred seventy eight blood, and effusion, samples were collected from patients with accumulated effusion. Three milliliter of blood and twenty milliliter of serous effusion samples were prepared according to the Conventional PAP Smear, Enzyme-linked Immune-sorbent Assay ELISA, and Immunocytochemistry ICC techniques. Malignant serous effusions were observed in 121 (62%) samples, among which 75 (62%) were in females samples and 46 (38%) were in males samples. The calculated means for all markers levels in effusion and blood samples between benign and malignant individuals showed statistical significant differences with P-value= (0.000). Except NSE blood samples level which showed no statistical significant difference with P- value= (0.665). High Pearson’s Correlation was observed between CEA effusion level and CA15-3 blood level with r=0.867. Sensitivity and specificity analysis for the tumor markers in the blood samples revealed the following values, EMA 80.1% and 82.4% , CA15- 3 77.6% and 59.6%, CEA 71% and 59.6%, and NSE 42.1% and 52.6% respectively. Whereas, the effusion samples analysis revealed the following sensitivity and specificity values, CA15-3 89.2%, and 91.2%, EMA 82.6%, and 45.6%, CEA 80.1%, and 68.4%, and NSE 66.1%, and 42.1% respectively. While the immune-staining analysis revealed the following sensitivity and specificity values, EMA 90.9% and 50.8%, CA15-3 83.4% and 84.2%, CEA 72.7% and 94.7%, And NSE 68.5% and 70.1% respectively. The receiver operating characteristic (ROC) curves revealed that; areas under the curve for the markers were as follows: EMA as 0.881and 0.869, CA15-3 as 0.867 and 0.960, CEA as 0.765 and 0.829, and NSE as 0.511 and 0.745 in blood and effusion samples respectively. On the basis of this study, validation of tumor markers proved to have has an essential impact in the diagnosis of malignant effusion and patients’ management, nevertheless, flow cytometry, automated image morphometry should be incorporated in the diagnosis of doubtful effusions which will improve the diagnostic sensitivity and specificity in this setting and help solving the everlasting dilemma of the malignant effusions.