Activity of Matrix Metalloproteinases‐2 and ‐9 in Advanced Laryngeal Cancer

OBJECTIVES: Matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) are proteolytic enzymes that digest collagen type IV and other components of the basement membrane. They play a key role in local invasion and the formation of distant metastases by malignant tumors. The aim of this study was to evaluate the activity of MMP-2 and MMP-9 in stage III and IV laryngeal cancers. STUDY DESIGN: In the study we used specimens of laryngeal cancer and surrounding normal mucosa obtained from 23 patients undergoing surgical treatment as a primary therapy. After extraction of MMP-2 and MMP-9 from tissue samples, their activity was assessed with zymography. RESULTS: Greater activity of MMP-2 and MMP-9 and a higher active/latent MMP-2 ratio were found in cancer compared with normal mucosa. Moreover, N2 tumors revealed greater activity of MMP-2 in comparison with N1 and N0 tumors. CONCLUSIONS: Results of the study indicate that both MMP-2 and MMP-9 may be involved in the expansion of laryngeal cancer. MMP-2 may also play an important role in the lymphatic spread of some laryngeal tumors.