Urinary levels of urokinase-type plasminogen activator and its receptor in the detection of bladder carcinoma

Abstract

Background: The authors found previously that plasma levels of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) were elevated in patients with bladder carcinoma and were associated with features of biologically aggressive disease. In the current study, they tested the hypothesis that elevated urinary levels of uPA and uPAR would predict the presence of bladder malignancy by comparing the performance of uPA and uPAR with the performance of bladder wash-out cytology in the noninvasive diagnosis of bladder tumors.

Methods: An enzyme-linked immunosorbent assay was used to compare levels of uPA and uPAR in urine that was collected before cystoscopy from 122 patients with bladder carcinoma and from 107 participants in a control group. Seventy-two patients had clinical Tis or Ta transitional cell carcinoma, and 50 patients had invasive disease (>or= T1); 85 patients had clinical Grade 1-2 tumors, and 37 patients had Grade 3 tumors. For cytology, only high grade was considered positive.

Results: Urinary levels of uPA and uPAR were higher in patients with bladder carcinoma compared with levels in the control group (P < 0.001 and P = 0.016, respectively). However, only uPA levels were elevated in patients with abnormal urinary cytology (P = 0.006). After controlling for cytology (odds ratio [OR], 10.182; 95% confidence interval [95%CI], 4.451-23.291; P < 0.001), uPAR (P for trend = 0.168), and age (P = 0.091), those in the highest quartile for uPA had an increased risk of bladder carcinoma compared with those in the lowest quartile (OR, 3.022; 95%CI, 1.295-7.054; P for trend = 0.031).

Conclusions: The current findings suggest that urinary levels of uPA, but not uPAR, are related to the risk of bladder carcinoma. The study confirmed the central role of urinary cytology in the noninvasive diagnosis of bladder carcinoma.