MMP-1 is a prognostic marker for hematogenous metastasis of colorectal cancer.

BACKGROUND Degradation of basement membrane and extracellular matrix by matrix metalloproteinases (MMPs) is believed to be an essential step in the complicated process of hematogenous metastasis. MMP-1 is a member of collagenases, a family of MMPs that degrades collagens type I, II, and III, main components of the interstitial stroma. The purpose of this study was to investigate the expression of MMP-1 in colorectal cancer and its correlation with hematogenous metastasis. Patients and Methods. We examined 133 cases of colorectal cancer (Dukes A: 72; Dukes B: 26; Dukes C: 23; Dukes D: 12). Sections were cut from formalin-fixed, paraffin-embedded samples containing the deepest site of cancer invasion and stained immunohistochemically with a monoclonal antibody to MMP-1. According to the area of the tumor that was stained, patients were divided into high- and low-MMP-1 expression groups. RESULTS MMP-1 expression was observed in the cytoplasm of cancer cells, some stromal cells, and a few normal epithelial cells of colonic mucosa. High MMP-1 expression was found in 47 (35.3%) cases and low in 86 (64.7%). Hematogenous metastasis was identified in 14 (29.8%) of high-MMP-1 groups and 12 (13.9%) of low-MMP-1 groups. MMP-1 expression significantly correlated with hematogenous metastasis of colorectal cancer, but no correlation was found between MMP-1 expression and the other clinicopathological features investigated. CONCLUSIONS MMP-1 expression may be a novel marker for hematogenous metastasis of colorectal cancer, and its inhibition may be a strategy for prevention of metastasis.