THE PLASMINOGEN-ACTIVATION SYSTEM IN OVARIAN-TUMORS

We studied the plasminogen activation system in tumor tissue by measur ing the antigen level of the 2 plasminogen activators, tissue-type (t- PA) and urokinase-type (U-PA) and their inhibitors, plasminogen-activa tor inhibitors type-I (PAI-1) and type-2 (PAI-2) in the tissue extract s of 43 human benign and malignant ovarian tumors. U-PA levels were si gnificantly higher in malignant than in benign tumors. In addition, U- PA antigen levels were higher in the metastatic tissue of advanced dis ease (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 significa nt. In contrast, t-PA levels were lower in metastatic than in non-meta static tumors, whereas PAI-2 levels were unrelated to the stage of ova rian malignancy. These results were integrated in a plasminogen-activa tion-dependent malignancy index (U-PA x PAI-1/t-PA). This index distin guished the different groups of benign ovarian tumors, localized and m etastatic ovarian carcinomas better than U-PA levels. It could be usef ul as a prognostic indicator in ovarian cancer. (C) 1993 Wiley-Liss, I nc.