Background: The aim of this study was to analyze the concentrations of different components of the plasminogen activation system in cyst fluid from malignant, borderline and benign ovarian tumors and to compare these results with clinicopathological characteristics (FIGO staging, histological grading, residual tumor, ascites, tumor recurrence and disease-free survival).
Materials and methods: One hundred and seven cyst fluid samples were enrolled from 25 malignant, 12 borderline and 70 benign ovarian tumors. Determination of uPA, tPA, PAI-1, PAI-2, uPA:PAI-1 complex and tPA:PAI-1 complex was performed by specific double determinant ELISAs based on the concept described previously by Grebenschikov et al. With these ELISAs both complexes of the activators (uPA, tPA) with their inhibitor (PAI-1) can be measured as a separate component.
Results: Significant differences were found in median cyst fluid concentrations of uPA, PAI-1, uPA:PAI-1 and tPA:PAI-1 from malignant, borderline and benign ovarian tumors, with the highest levels in malignant ovarian tumors. Cystic endometriosis seems to be a special entity within the benign subclass. To achieve better discrimination between malignant and benign cases we introduced a new malignancy index: ([uPA:PAI-1]+[tPA:PAI-1])x [PAI-1]. The area under a Receiver Operating Characteristic (ROC) curve amounted to 0.80. Significantly higher concentrations were found in FIGO stages II-III-IV compared with stage I for uPA (p<0.05), tPA (p<0.05), uPA:PAI-1 (p<0.01) and tPA:PAI-1 (p<0.05).
Conclusion: Concentrations of plasminogen activation system markers in cyst fluid from ovarian tumors are related to histological subtype. The most significant components are uPA, PAI-1 and the complexes uPA:PAI-1, tPA:PAI-1. The prognostic value of the components seems to be limited but might be important in detecting high-risk borderline or low stage patients.