Plasminogen activators and steroid receptor concentrations in normal, benign, and malignant breast and ovarian...

The plasminogen activator (PA) activity and oestrogen and progestin receptor concentrations were determined in normal, benign and malignant tissues of human breast and ovary. The geometric mean of PA activity was significantly higher (p less than 0.05) in malignant than in normal breast tissue specimens. PA activity was also higher in benign breast tumours than in normal tissue, but lower than in malignant tumours. The geometric means of PA activity in normal, benign and malignant ovarian tissue specimens differed even more clearly (analysis of variance: p less than 0.001). There was no significant correlation between PA activity and cytosol oestrogen or progestin receptor concentrations in either breast or ovarian cancer tissues. Our data confirm the finding that increased tissue PA activity is associated with human malignant breast tumours, compared with normal tissue and benign mammary lesions, and show that a similar situation prevails in human ovarian tissues. In addition, they show that the possible female sex steroid dependency of PA activity in human breast and ovarian malignancies cannot be demonstrated by cytosol receptor assays alone.