Matrix metalloproteinase-9 is associated with disease-free survival and overall survival in patients with gastric cancer

Matrix metalloproteinase-9 is a member of the Matrix metalloproteinases (MMP) family, which is overexpressed in some solid tumor and thought to enhance the tumor invasion and metastasis ability. Our study is to investigate the association of MMP-9 expression with disease-free survival and overall survival of patients with gastric cancer. Clinical gastric cancer specimens and adjacent normal tissues from 286 patients who had not received neoadjuvant chemotherapy were investigated by immunohistochemistry assay. Staining evaluation results were analyzed statistically in relation to various clinicopathological characters, disease-free survival and overall survival. High level of MMP-9 expression was detected in gastric cancer, significantly more than in adjacent normal epithelial cells. In gastric 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 patients' age, sex, tumor location or differentiation status were detected. The disease-free survival and overall survival were significantly shorter for patients with MMP-9 positive than those with MMP-9 negative tumors. Multivariate analysis identified MMP-9 was an independent prognostic factor for both disease-free survival and overall survival. Our findings provided convincing evidence for MMP-9 as an important role in human gastric cancer recurrence and prognosis. It might also serve as a novel target for both prognostic prediction and therapeutics.