Nipple aspirate fluid expression of urokinase-type plasminogen activator, plasminogen activator inhibitor-1, and urokinase-type plasminogen activator receptor predicts breast cancer diagnosis and advanced disease.

Background: Tumor expression of urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and uPA receptor (uPAR) are breast cancer prognostic factors. Less is known about their usefulness in breast cancer diagnosis. Nipple aspirate fluid (NAF) is secreted into the breast duct and collected noninvasively, making it potentially useful both in breast cancer diagnosis and prognosis. We determined the association of uPA, PAI-1, and uPAR levels in NAF with breast cancer (1) detection and (2) advanced disease.
Methods: A total of 88 NAF specimens were collected from women with or without breast cancer, and uPA, PAI-1, and uPAR expression were measured by enzyme-linked immunosorbent assay.
Results: uPA and uPAR were independent predictors of cancer presence; uPAR was also an independent predictor of advanced disease stage. Higher PAI-1 expression in breast cancer that was found with univariate analysis was not observed after logistic regression was applied.
Conclusions: NAF evaluation of uPA, uPAR, and, perhaps, PAI-1 (significant only in univariate analysis) may provide useful breast cancer diagnostic and prognostic information.