THE PLASMINOGEN-ACTIVATION SYSTEM IN OVARIAN-TUMORS

We studied the plasminogen activation system in tumor tissue by measuring the antigen level of the 2 plasminogen activators, tissue-type (t-PA) and urokinase-type (U-PA) and their inhibitors, plasminogen-activator inhibitors type-I (PAI-1) and type-2 (PAI-2) in the tissue extracts of 43 human benign and malignant ovarian tumors. U-PA levels were significantly higher in malignant than in benign tumors. In addition, U-PA antigen levels were higher in the metastatic tissue of advanced disease (FIGO stage III) than in the primary localized tumor (FIGO stage I/II). Also PAI-1 concentrations tended to be higher in malignant than in benign tumors, but this difference was not statistically significant. In contrast, t-PA levels were lower in metastatic than in non-metastatic tumors, whereas PAI-2 levels were unrelated to the stage of ovarian malignancy. These results were integrated in a plasminogen-activation-dependent malignancy index (U-PA x PAI-1/t-PA). This index distinguished the different groups of benign ovarian tumors, localized and metastatic ovarian carcinomas better than U-PA levels. It could be useful as a prognostic indicator in ovarian cancer. (C) 1993 Wiley-Liss, Inc.