UROKINASE-TYPE PLASMINOGEN-ACTIVATOR RECEPTOR IS A NOVEL PROGNOSTIC FACTOR IN BREAST-CANCER

Background: There have been many reports that the u-PA system plays an important role in cancer invasion and metastasis. The binding of u-PA to its specific cell-surface receptor, u-PAR, is necessary for the ac tivation of u-PA system. The aim of this study is to evaluate the role and the prognostic value of u-PAR in cancer invasion and metastasis. Patients and Methods: u-PAR expression in 104 breast cancers was inves tigated immunohistochemically using a monoclonal antibody against u-PA R Results: u-PAR expression was mainly observed both on cancer cells a nd stromal cells. Patients with high u-PAR expression in cancer cells or stromal cells had a high relapse rate compared with patients with l ow u-PAR expression by the Kaplan-Meier method (p=0.035 and 0.011, res pectively). In uni- and multivariate analysis u-PAR expression in stro mal cells was significantly correlated with relapse (p=0.017 and 0.043 , respectively). Conclusions: This study has shown that not only cance r cells but also stromal cells have an important roles in breast cance r invasion and metastasis, and that u-PAR expression in cancer cells a nd stromal cells might be a novel prognostic factor in breast cancer.