Matrix metalloproteinases (MMPs) are a large family of proteolytic enzymes, which are in volved in the degradation of many different components of the extracellular matrix. There is increasing evidence indicating that individual MMPs have important roles in tumor invasion and metastasis. A tissue inhibitor of metalloproteinase(TIMPs) has been reported to inhibit tumor invasion by inactivating the MMPs. In this study, the correlation between MMPs and TIMPs expression, and the clinical outcome was investigated.

Immunohistochemical staining of MMP-2,9 and TIMP-1,2 were performed on paraffin-embedded tumor sections from 74 resected primary non-small cell lung cancers.

In 74 patients, MMP-2, MMP-9, TIMP-1, and TIMP-2 immunoreactivity was demonstrated in 24 (34%), 19(26%), 27(36%) and 32(43%) of the paraffin-embedded tumors, respectively. The median survival of the MMP-2 positive cases was significantly shorter than that of the negative cases(20 vs 34 months). The median survival of the TIMP-2 positive cases was also was significantly longer than that of negative case (34 vs 18 months). The MMP-2, and MMP-9 expression level had a positively correlation with a more advanced stage and lymph node metastasis. There was inverse correlation between TIMP-2 expression and tumor invasion. The median survival of the MMP-2 negative/TIMP-2 positive cases was higher than that of the other cases.

These results suggest that tumor invasion and lymph node metastasis are closely related to MMP-2 and MMP-9 expression. There was an inverse correlation between TIMP-2 MMP-9 expression, and tumor invasion.