Objectives. A number of studies have demonstrated that urokinase-type
plasminogen activator (u-PA) is one of the major enzymes in the develo
pment of cancer invasion and metastasis. We examined the possibility t
hat u-PA content is an independent prognostic marker for superficial b
ladder cancer. Methods. The u-PA content was estimated in superficial
bladder cancer from 52 patients undergoing transurethral resection for
the first time. The survival rates of the patients were calculated an
d the prognostic values for u-PA content (less than 8 ng/mg protein ve
rsus more than 8 ng/mg), Stage (pTa or pT1), grade (1 and 2 versus 3),
number (single versus multiple), and size (less than 1 cm versus more
than 1 cm) of tumor were determined by a multivariate regression mode
l. Results. Development of cancer invasion and metastasis was observed
in 3 and 8 patients, respectively. The survival rate of the patients
with high u-PA content was significantly lower than those with low u-P
A content (P < 0.005), In the multivariate regression analysis, u-PA c
ontent was the most important risk factor for the prognosis, compared
with the other factors: tumor stage, grade, multiplicity, and size. Co
nclusions. We have first shown that u-PA content is a new independent
prognostic marker in patients with superficial bladder cancer.