Urokinase plasminogen activator: a prognostic marker in breast cancer including patients with axillary node-negative disease.

Urokinase plasminogen activator (uPA) is a serine protease causally involved in cancer invasion and metastasis. In this study, high concentrations of uPA in primary breast cancers were independently associated with both a shortened disease-free interval and overall survival. For the disease-free interval as endpoint, uPA was a stronger indicator of outcome than lymph node status, whereas for overall survival, nodal status was stronger than uPA. In patients without metastasis to axillary nodes, uPA was also an independent prognostic marker, using both the disease-free interval and overall survival as end points. In contrast to uPA, neither tumor size nor estrogen receptor status was prognostic in the node-negative patients. Measurement of uPA concentrations might thus be of value in selecting the more aggressive subpopulation of node-negative breast cancer patients that could benefit from adjuvant therapy.