Matrix metalloproteinase-9 overexpression is closely related to poor prognosis in patients with colon cancer

Background: Matrix metalloproteinase-9 (MMP-9) is an important member of the matrix metalloproteinase family and is considered to be involved in the invasion and metastasis of cancer cells. This study analyzed the expression of MMP-9 in colon cancer patients and the relationship between this expression and clinicopathological features and survival. Methods: We immunohistochemically investigated 68 specimens of colon cancer tissues and corresponding distal normal mucosa tissues using MMP-9 antibody. Then, the correlation between MMP-9 expression and clinicopathological features and its prognostic relevance were determined. Results: The expression rate of MMP-9 in colon cancer tissues was significantly higher than that in distal normal mucosa (69.1% versus 2.9%, P < 0.001). Significant correlations were only found between high levels of MMP-9 expression and metastasis of lymph nodes and Dukes' stage. Overexpression of MMP-9 was associated with shorter survival times in univariate analysis. Multivariate analysis confirmed that MMP-9 expression was an independent prognostic factor. Conclusions: MMP-9 is correlated with the metastasis of lymph nodes, and its elevated expression may be an adverse prognostic indicator for the patients of colon cancer.