[Tissue plasminogen activator activity in early prostatic cancer and in bone metastases of prostatic cancer]

Most malignant cells exhibit increased plasminogen activator activity which, in turn, leads to the formation of the fibrinolytically active enzyme, plasmin. Since solid tumours in man are surrounded by a fibrin network, the fibrinolytic activity of the tumour may influence tumour growth and metastasis. In the present study plasminogen activator activity, as assessed in purified extracts, was compared in benign hyperplasia of the prostate (group A, n = 6), non-metastasizing+ prostatic carcinoma (group B, n = 26), and in prostatic carcinoma with bone metastasis (group C, n = 10). Plasminogen activator activity was significantly higher in prostatic carcinoma than in hyperplasia, but there was no significant difference in plasminogen activator activity between prostate carcinoma with or without bone metastasis. However, plasminogen activator activity in the bone metastasis cells was significantly higher than in the primary tumour. If a positive correlation between fibrinolytic activity of the tumour and the metastasizing capacity were postulated, particular importance could be attached to bone metastasis in prostatic cancer.