Expression of matrix metalloproteinase-9 (MMP-9) and blood vessel density in laryngeal squamous cell carcinomas

Conclusion: In this study we found that inflammatory cells may be a source of MMP-9 in laryngeal cancer. MMP-9 was correlated with blood vessel density. MMP-9 may be a potential target to disrupt tumor neovascularization. Objective: To study the expression of MMP-9 in laryngeal cancer and determine a possible relation with blood vessel density. Methods: Immunohistochemistry was used for MMP analysis and for blood vessel detection in 83 laryngeal cancer samples. The density of blood vessels was analyzed with a stereological tool. Results: MMP-9 was detected in inflammatory cells. Positivity for MMP-9 correlated significantly with the grade of differentiation (p = 0.025). Expression of MMP-9 was not correlated with T stage, nodal metastasis, or tumor recurrence. The mean blood vessel density was 51.4 vessels/mm(2). Specimens were more likely to exhibit higher density of blood vessels when MMP-9 expression was also present (p = 0.014).