PLASMINOGEN ACTIVATORS AND PLASMINOGEN-ACTIVATOR INHIBITOR-1 IN URINARY-TRACT CANCER

The plasminogen activation system is considered to play an important r ole in cancer growth and metastasis. Both plasminogen activators (PAs) and their fast-acting inhibitors are produced in tumor cells and thei r surrounding tissues. In order to clarify the influence of the existe nce of malignant tumor in urinary tract on the systemic fibrinolytic a ctivity, we designed a study in which we compared the plasma levels of PAs and their inhibitors between before and after radical resection o f tumors. Fourteen patients with renal cell carcinoma and 14 patients with transitional cell carcinoma participated in the study. In both gr oups,: plasma levels of tissue-type plasminogen activator and urokinas e-type plasminogen activator before the operation were higher than tho se 15 days after operation. The plasma level of plasminogen activator inhibitor 1 (PAI-1), however, did not change after the operation in th e renal cell carcinoma group, and it decreased slightly in the transit ional cell carcinoma group although it was not significant. When these values of the groups with or without metastasis were compared to othe r organs or lymph nodes, the PAI-1 level before operation was signific antly higher in the group with metastasis than that without metastasis . In the three groups divided by the degree of atypia, PAI-1 level in the most atypical group was the highest. These results suggest that th e fibrinolytic system in the plasma of cancer patients may play an imp ortant role in tumor growth and metastasis.