Prognostic Value of Matrix Metalloproteinase-9 in Gastric Cancer: A Meta-Analysis

Background/Aims: The purpose of this study was to evaluate the effect of matrix metalloproteinase-9 overexpression on clinical outcome of gastric cancer using a meta-analysis. Methodology: Relevant studies concerning the association between Matrix metalloproteinase-9 expression and survival of patients with gastric cancer were collected from electronic databases. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to estimate the association. Subgroup analysis was calculated to evaluate potential sources of heterogeneity. Besides, we also assessed the relationship between Matrix metalloproteinase-9 level and relevant clinicopathological parameters by estimating the Odds ratios (ORs) with 95% CIs. Results: Ten studies with 1,478 patients were included to perform a meta-analysis of the survival results. Pooled HRs indicated that MMP-9 overexpression had a negative impact on the over survival (OS) of patients with gastric cancer (HR = 1.69, 95% CI: 1.29-2.23, P = 0.00), without significant heterogeneity (chi(2) = 14.17, I-2 = 36.5%, P = 0.117). Similarly high level of MMP-9 tended, to be correlated with lymph node metastasis (OR = 1.91, 95% CI: 1.40-2.59, P < 0.05) and presence of vascular invasion (OR = 2.64, 95% CI: 1.52-4.59, P < 0.05). Conclusions: This meta-analysis shows that Matrix metalloproteinase-9 overexpression is a poor prognostic factor in patients with gastric cancer. However, larger scale and randomized studies are needed to confirm its potential clinical value.