Matrix metalloproteinase/tissue inhibitorsof matrix metalloproteinase phenotype identifies poor prognosis colorectal cancers

Purpose: The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes involved in tumor invasion; several individual members of which have been implicated in tumor prognosis. These enzymes and their physiologic inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), act in a coordinated manner to form an integrated system. Therefore, to understand their role in tumor invasion, it is necessary to evaluate them collectively.

Experimental Design: In this study all of the major members of the matrix metalloproteinase (MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MMP-13, MT1-MMP and MT2-MMP)/tissue inhibitor of matrix metalloproteinase (TIMP-1, TIMP-2, and TIMP-3) system have been investigated by immunohistochemistry in a series (n = 90) of stage III (Dukes' C) colorectal cancers. An immunohistochemical score based on the intensity of immunoreactivity and proportion of immunoreactive cells was established for each MMP and TIMP.

Results: The MMP/TIMP profile defined by hierarchical cluster analysis of the immunohistochemical score identifies a distinct group of colorectal cancers with poor prognosis (log-rank test, 12.22, P = 0.0005). The median survival time of patients in this survival group was 18 months compared with a median survival of 49 months in the "good" survival group. Multivariate analysis showed that this profile was independently the most significant prognostic factor (P = 0.001).

Conclusions: This study has identified that the MMP/TIMP profile is an independent indicator of poor prognosis in colorectal cancer.