Comparison of Matrix Metalloproteinases 2 and 9 Levels in Saliva and Serum of Patients with Head and Neck Squamous Cell Carcinoma and Healthy Subjects

Head and neck squamous cell carcinoma (HNSCC) is the sixth common cancer worldwide. A hallmark of cancer progression is degradation of the extracellular matrix by matrix metalloproteinases (MMPs) that allows cancer cells to invade the surrounding tissue. The purpose of this study was to evaluate the levels of MMP-2 and 9 in serum and salivary of HNSCC patients and compare it with a healthy group. Twenty patients with newly diagnosed HNSCC, who had not received any treatment, referred to Omid and Ghaem hospitals, Mashhad, Iran, and twenty healthy controls were voluntarily included in this study. Salivary and blood samples were collected from both groups and the concentration of MMP-2 and MMP-9 were measured by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed by SPSS using Student t-test or Mann-Whitney with significance level of ≤ 0.05. In cancer patients, the serum level of MMP-9 was significantly higher than that of in the healthy group (P < 0.001). However, salivary MMP-9 was higher in cancer patients, this difference was not significant (P = 0.736). There was no significant difference between the study groups for the levels of serum (P = 0.283) and salivary MMP-2 (P = 0.764). There was a correlation between salivary and serum levels of both markers in cancer patients (P = 0.046 and P = 0.011 for MMP-2 and MMP-9, respectively), on the contrary, there was not a correlation between them in the healthy controls (P = 0.628 and P = 0.064, for MMP-2 and MMP-9, respectively). A direct correlation between the salivary level of MMP-9 and tumor grade was also detected (P = 0.045). The salivary analysis indicates that an altered composition for MMPs in HNSCC, suggesting a potential diagnostic tool for oral cancer. The serum level of MMP-9 appears to be a reliable marker for early diagnosis in HNSCC patients.