Overexpression of matrix metalloproteinase-7 and -9 in NSCLC tumor and stromal cells: correlation with a favorable clinical outcome.

Background: Matrix metalloproteinases (MMPs) are considered important players in angiogenesis and cancer progression. Several drugs developed for targeting MMPs have until now been without clinical efficacy. As both malignant cells and cells of the surrounding stroma contribute to tumor growth, we have explored the impact of MMP-2, -7 and -9 expression in both the tumor and stromal compartment of non-small-cell lung cancers (NSCLC).

Patients And Methods: From 335 unselected stage I to IIIA NSCLC carcinomas, duplicate tumor and tumor-associated stromal cores were collected in tissue microarrays (TMAs). Immunohistochemistry was used to detect the expression of MMP-2, -7 and -9 in tumor and stromal cells.

Results: In univariate analyses, high tumor cell MMP-7 expression (P=0.029) and high stromal MMP-9 expression (P=0.001) were positive prognostic factors. In the multivariate analysis, high tumor cell MMP-7 expression (HR 1.58, CI 1.08-2.32, P=0.020) and high stromal MMP-9 expression (HR 1.92, CI 1.25-2.96, P=0.003) were independent positive prognostic factors for disease-specific survival.

Conclusion: High levels of MMP-7 in tumor cells and high levels of MMP-9 in tumor associated stroma were independent positive prognostic factors in NSCLC patients.