Serum Level of Matrix Metalloproteinase-9 in Patients with Head and Neck Squamous Cell Carcinoma

Background: Head and neck squamous cell carcinoma (HNSCC) is characterized by the upregulation of a large number of matrix metalloproteinases (MMPs). The aim of the study was to investigate the level of MMP-9 in the sera of HNSCC patients and its relationship to clinicopathological features. Methods: Serum samples from sixty-five patients (56M/9F, 59.11 +/- 9.02 years) with HNSCC were quantitatively measured by ELISA assay, before and two days after surgery. Forty healthy volunteers served as controls (29M/11F, 56.21 +/- 12.13 years). Results: Median serum concentrations of MMP-9 were consistently upregulated in HNSCC patients both preoperatively (1593.0 ng/mL, IQR: 833.0 - 1942.0 ng/mL) and postoperatively (1382.0 ng/mL, IQR: 778.6 - 2062.0 ng/mL) in comparison to healthy controls (291.3 ng/mL, IQR: 223.8 - 330.5 ng/mL) (p < 0.001). Pretreatment levels of MMP-9 were related to the size of primary tumor (p = 0.018) and lymph node involvement (p = 0.045). No statistically significant association was found between serum MMP-9 concentrations and clinical stage or degree of differentiation of the tumor cells. Conclusions: Serum MMP-9 level could be used as a diagnostic tool for early detection of HNSCC and for determining prognosis. Moreover, our results suggest that MMP-9 might be a good marker in evaluating the size of the primary tumor and lymph node involvement. Further studies are needed to show whether MMP-9 could serve as a marker for recurrence.