UROKINASE-PLASMINOGEN-ACTIVATOR LEVELS AND PROGNOSIS IN 69 SOFT-TISSUE SARCOMAS

The local and systemic invasiveness of soft-tissue sarcomas may depend upon an interaction between the primary tumour and the extracellular matrix in which the proteolytic enzyme, urokinase plasminogen activato r (uPA), may have an important role. We analyzed the expression of uPA in soft-tissue sarcoma using a luminescent immunoassay technique, and examined the relationships between different uPA levels and tumour ch aracteristics and behaviour. We evaluated 69 adult patients with surgi cally treated soft-tissue sarcomas (MFH 43, leiomyosarcoma 8, liposarc oma 5, synovial sarcoma 4, others 9) of the extremities and trunk wall . Sixteen developed local recurrences, 26 developed metastases, and 5 had both. The median follow-up for survivors was 55 (30-80) months. Th e median uPA level was 1.4 (0.04-10.6) ng/mg protein. Increasing uPA l evels correlated with increasing grade, malignant fibrous histiocytoma s, leiomyosarcomas, DNA non-diploidy, tumour necrosis, local recurrenc e, and metastasis. Storiform-pleomorphic MFH had higher uPA levels tha n the myxoid variant. A cut-off value of 0.25 ng/mg protein was identi fied, above which local recurrence and metastasis occurred more freque ntly. High uPA levels appear to reflect the malignant phenotype in sof t-tissue sarcoma, thus supporting the role of uPA as a prognostic indi cator. (C) 1996 Wiley-Liss, Inc.