The content of urokinase-type plasminogen activator antigen as a prognostic factor in urinary bladder cancer.

Urokinase-type plasminogen activator (u-PA) is thought to be implicated in cancer invasion and metastasis. The aim of this study was to determine whether the u-PA content of cancer tissue is a prognostic factor in bladder cancer. Tissue samples from 46 patients with bladder cancer were assessed for u-PA antigen by a highly sensitive enzyme immunoassay. The relationships between the u-PA level in extracts of bladder cancer and the survival rates of the bladder-cancer patients were examined. Patients with a high u-PA level (8 ng/mg of protein and more) showed a statistically significantly higher rate of survival than those with a low u-PA level (p less than 0.005). The u-PA antigen level in cancer tissue was significantly lower in low-graded and non-invasive cancers than in others (p less than 0.01).