Matrix metalloproteinases as prognostic markers in oral squamous cell carcinoma: A systematic review, meta-analysis and meta regression of MMP-2, MMP-7, and MMP-9 expression and their serum and saliva concentrations.

Matrix metalloproteinases (MMPs), especially MMP-2, MMP-7, and MMP-9, have key roles in breaking down of extracellular matrix components and participate in tumor invasion, metastasis, and poor prognosis in oral squamous cell carcinoma (OSCC). The main objective of this study was to systematically review and quantitatively synthesize available evidence on the expression of MMP-2, MMP-7, and MMP-9 in OSCC tissues, as well as their concentrations in serum and saliva, in order to assess their potential as diagnostic and prognostic biomarkers and to explore factors influencing their levels across different populations. The study followed PRISMA guidelines, and relevant English-language studies were identified with the help of a comprehensive search of six major databases. Studies were included with the data for MMP-2, MMP-7, or MMP-9 in OSCC tissues, serum, or saliva and had measurable outcomes. A total of 28 eligible studies were analyzed. The analyses showed significant expression of MMPs [0.085, CI 95 % (0.067-0107); I = 22.57; P = 0.000; Q = 45.20]. The analyses also showed significant concentration of MMPs [1.62, CI 95 % (0.90-2.33); I = 96.38; P = 0.000; Q = 46.81]. Meta-regression analysis showed that geographic region had a significant effect on MMP concentrations, with higher values for studies from Pakistan. However, other factors such as patient age, sampling location, and type of MMP were not statistically significant moderators. These findings support the potential of MMPs as prognostic biomarkers for OSCC. Differences between regions highlight the need for considering local factors in both clinical evaluation and future research design.