MMP-9 expression levels and the pathological differentiation of oral squamous cell carcinoma (OSCC): a meta-analysis

The purpose of this study is to evaluate the association of MMP-9 expression levels with the pathological parameters in the differentiation of oral squamous cell carcinoma (OSCC). Literature retrieval, selection and assessment, data extraction, and meta-analyses were performed according to the RevMan 5.3 guidelines. We used odds ratios (ORs) and 95% confidence intervals (CIs) to assess the association of MMP-9 expression levels with the differentiation degree of OSCC based on the results of a heterogeneity test. Nine eligible studies including 468 OSCC patients were analyzed. Statistically significant positive associations were found between high MMP-9 expression levels and poorer OSCC differentiation degrees (OR=2.15, 95% CI: 1.40-3.29; P=0.0005). Our meta-analysis shows that a high level of MMP-9 expression is an important sensitive coincident indicator for the poorer differentiation degree of OSCC.