Prognostic value of matrix metalloproteinase 9 expression in patients with non-small cell lung cancer.

The role of matrix metalloproteinase 9 (MMP-9) expression in non-small cell lung cancer (NSCLC) remains controversial. We performed a systematic review of the literature with meta-analysis.Electronic databases were used to identify published studies before December 1, 2011. Pooled hazard ratio (HR) with 95% confidence interval (95% CI) was used to estimate the strength of the association between MMP-9 expression survival of NSCLC patients. Heterogeneity and publication bias were also assessed.The final analysis of 2029 NSCLC cases from 17 studies is presented. The combined HR of 1.84 (95% CI: 1.62-2.09) suggested that MMP-9 over-expression had a poor prognosis in patients with NSCLC. Subgroup analyses also detected significant association. Heterogeneity and publication bias was absent in current meta-analysis. Sensitivity analyses suggested that the summary statistics obtained should approximate the actual average.High MMP-9 expression is associated with a poor prognosis in patients with NSCLC.