UROKINASE-TYPE PLASMINOGEN-ACTIVATOR EXPRESSION IN HUMAN PROSTATE CARCINOMAS

The prostate gland is the most common site of cancer in men in the Uni ted States. The biologic behavior of an individual tumor, however, var ies widely, with some cancers taking a relatively indolent course and others progressing rapidly to disseminated disease. Prognostic factors that might help predict a tumor's aggressiveness and invasiveness are limited. The expression of urokinase plasminogen activator was evalua ted in 36 human prostate cancer specimens. Using an immunohistochemica l method with monoclonal antibody #394, 70.6% (12 of 17) of cancer spe cimens with extracapsular extension showed increased expression of uro kinase plasminogen activator, compared with 26.6% (4 of 15) of specime ns without capsular invasion. Increased expression was localized to th e glandular cytoplasm, with tumor stroma yielding predominantly negati ve results. These findings provide additional evidence of the role of urokinase in determining the biologic behavior and metastatic potentia l of prostate cancer.