Clinical relevance of plasma matrix metalloproteinase-2 levels in primary invasive breast cancer

Abstract

9680 Background: Matrix metalloproteinases (MMPs) belong to a family of enzymes involved in degradation of the extracellular matrix, a key event in tumor progression, invasion and metastasis. Upregulated expression of MMPs is observed in tumor tissue of different cancers and high levels were found in serum and plasma of many cancer patients. The 2 gelatinolytic MMPs, MMP-2 and MMP-9 specifically degrade the basement membrane and may be the most important MMPs in tumor progression. Methods: We therefore studied the correlation between plasma MMP-2 levels of patients with newly diagnosed invasive breast cancer and several clinicopathological factors. We developed a MMP-2 Enzyme-Linked immunoassay on the Gyros Bioaffy system, using only very low amounts of plasma, i.e. 400 nanoliter per data point. After optimalisation and validation, this MMP-2 immunoassay was used to study plasma samples taken at time of diagnosis in 69 breast cancer patients before any treatment. Results: Using non parametric statistics, no significant correlation was found between plasma MMP-2 levels and the main clinicopathological factors such as pathological tumor size (p=0,72), lymph node involvement, (p=0,59), hormone receptor status (p=0,90) and differentiation grade (p=0,67). Plasma MMP-2 levels didn’t differ significantly between the 17 patients with invasive lobular carcinoma and the 47 patients with invasive ductular carcinoma (p=0,36). The plasma MMP-2 levels didn’t differ significantly between patients with Her-2 negative and Her-2 strong positive expression (p=0,58). These results were confirmed by a commercial sELISA. Conclusions: Plasma MMP-2 levels in primary invasive breast cancers aren’t significantly related with pathological tumor size, lymph node involvement, hormone receptor status, differentiation grade, histopathological type or Her-2 expression. This work was supported by a grant from the EU, “Cancerdegradome”, contract no. 503297. No significant financial relationships to disclose.