Prognostic importance of PAI-1 in node negative breast cancer patients-Results after 10 years of follow up

The serine protease urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) play key roles in the proteolytic cascade involved in physiological and pathological degradation of the extracellular matrix. The aim of this study was to determine the prognostic importance of PAI-1 expression in tumor cells in node-negative breast cancer patients that did not receive adjuvant chemotherapy. We used immunohistochemistry (IHC) as a detection method. The study retrospectively included 133 ductal invasive breast cancer patients from the Clinical Hospital Center Zagreb, Croatia, surgically treated in a two-year interval (1998-1999) with 10 years of follow up. The Cox proportional hazard regression test with stepwise variable selection was used to calculate the relative effect of investigated data on patients' prognosis. Univariate analysis showed that all investigated factors, such as lymph node involvement (p = 0.025), tumor grade (p < 0.001), estrogen receptor status (p = 0.011), vascular invasion (p = 0.001), HER2 overexpression (p < 0.001), and proliferative index (p < 0.001). had a statistically significant influence on patients' OS. Multivariate statistical analysis showed that only HER-2 (p < 0.001) can be considered an independent, statistically significant poor prognostic factor. In patients with negative lymph nodes that did not receive adjuvant chemotherapy, we found a significant correlation in overall survival (p = 0.009), which is favorable for PAI-1 negative tumors. In conclusion, it seems that PAI-1 in primary breast cancer tissue correlates with disease aggressiveness and has a strong prognostic impact on primary breast cancer, and is a strong prognostic factor for node-negative patients that did not receive chemotherapy. (c) 2011 Elsevier GmbH. All rights reserved.