PLAU and cancer: Several guidelines, such as European Organisation for Research and Treatment of Cancer (EORTC), and the American Society of Clinical Oncology (ASCO) recommend the invasion and metastasis markers uPA and PAI-1 for risk assessment and treatment decision in node-negative (N0) breast cancer patients (Harbeck et al. 1990, 2002; Schmitt et al. 2010; Foekens et al. 2000).