Matrix metalloproteinase-9 is associated with relapse and prognosis of patients with colorectal cancer.

BACKGROUND

Matrix metalloproteinase-9 is a member of the MMP family, which is overexpressed in some solid tumors and is thought to enhance tumor invasion and metastasis ability. The present study aims to examine MMP-9 expression in human colorectal cancer and to determine its association with clinicopathological characteristics and prognosis.

METHODS

Colorectal cancer and adjacent normal tissues from 192 patients were investigated by immunohistochemical assay. Staining evaluation results were analyzed statistically in relation to various clinicopathological characters, disease-free survival, and overall survival.

RESULTS

High level of MMP-9 expression was detected in colorectal cancer, significantly more than in normal colorectal epithelial cells. In colorectal cancer, MMP-9 was significantly positively correlated with depth of invasion, lymph node metastasis, and distant metastasis. However, no correlations between MMP-9 expression and patient age, sex, tumor location or differentiation status were detected. Disease-free and overall survival were significantly poorer for patients with positive MMP-9 staining than for those with MMP-9-negative tumors.

CONCLUSIONS

Our findings emphasize the important role of MMP-9 in the invasion and metastasis process in human colorectal cancer. It could also serve as a novel prognostic marker that is independent of, and additive to, the tumor-node-metastasis (TNM) staging system.