Clinical significance of urokinase-type plasminogen activator (uPA) and its type-1 inhibitor (PAI-1) for metastatic sentinel lymph node involvement in breast cancer.

Unlabelled: Urokinase-type plasminogen activator (uPA) and its type-1 inhibitor (PAI-1) are key factors for tumor invasion and development of metastases in breast cancer. Prospective studies confirmed the prognostic significance of these factors for development of distant metastases. The predictive impact of uPA and PAI-1 for metastatic sentinel lymph node involvement is unclear.
Patients and Methods: Between 2006 and 2008 uPA and PAI-1 were measured in 184 out of 1,035 patients for primary breast cancer. uPA and PAI-1 were analyzed with an ELISA assay. Measured concentrations were considered as negative for uPA <3 ng/ml and for PAI-1 <14 ng/ml.
Results: In a retrospective analysis, 173/184 women had a negative sentinel lymph node and 11/184 women had a metastatic sentinel lymph node. From the 11 women with a positive sentinel lymph node 7 had elevated values for uPA and 4 had elevated values for PAI-1. Four and 7 women were uPA- and PAI-1-negative, respectively. Sensitivity, specificity, positive and negative predictive values for uPA were 63.3%, 50.9%, 7.6%, 95.6% and for PAI-1 36%, 52.6%, 4.7%, 92.9%. Even the combination of both uPA and PAI-1 values did not detect 3/11 women with metastatic lymph node involvement.
Conclusion: uPA and PAI-1 alone or in combination did not identify all patients with metastatic lymph node involvement. Thus, uPA and PAI-1 cannot be considered as predictive selection parameters to avoid sentinel lymph node biopsy in case of negative values for uPA or PAI-1.
(Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)