Background: Matrix Metalloproteinases (MMPs) have been implicated as playing an important role in cancer invasion and metastasis. MMPs have been identified in a wide variety of malignancies including head and neck squamous cell carcinomas (HNSCC).
Material and methods: We investigated the circulating level of MMP-2 (gelatinase A or 72-kD type IV collagenase) and MMP-9 (gelatinase B or 92-kD type IV collagenase) in sera from patients with various head and neck squamous cell carcinomas (n = 86) as well as from healthy normal controls (n = 47). Serum MMP concentrations were determined as serum immunoreactivity by using a quantitative sandwich enzyme immunoassay technique. For statistical analysis, the t-test and Kruskal-Wallis test were performed.
Results: The majority of the patients with HNSCC were found to have high concentrations of serum MMP-9. The levels of MMP-9 in the sera of patients with cancer ranged from 39 to 1547 ng/ml (mean, 417 ng/ml). In contrast, the MMP-9 serum levels in 47 healthy individuals ranged from 30 to 537 ng/ml (mean, 189 ng/ml), MMP-9 serum concentration being significantly higher in HNSCC patients (p = 0.001). MMP-9 serum concentrations of patients with advanced stage HNSCC were significantly higher (p = 0.0449) compared to patients with early stage cancer. No significant difference of MMP-2 serum levels was seen when comparing HNSCC patients and normal controls.
Conclusion: The present data indicate that the elevation of serum levels of MMP-9, but not MMP-2, may be a useful marker for clinical monitoring of HNSCC patients.