Association of infiltrating cells with microvessel density in oral squamous cell carcinoma

Several lines of evidence indicate that immune cells in the tumor microenvironment play an important role in regulating tumor progression. An immunohistochemical method was used to examine the abundance of natural killer (NK) cells, mucosal dendritic cells (DCs), macrophages, mast cells, and microvessel density in 78 cases of oral squamous cell carcinoma (OSCC): with better prognosis – OSCCBP (n = 37), and with poorer prognosis – OSCCPP (n = 41), and 18 controls. The mean numbers of macrophages and microvessels were significantly higher in the OSCCPP group in comparison to both OSCCBP and control groups. The mean number of NK cells, mast cells and DCs was lower in the OSCCPP group in comparison to the OSCCBP group, but there were no statistically significant differences between mean numbers of NK cells in tested groups. Statistically significant correlations between the number of DCs and NK cells and mast cells, as well as between microvessel density and numbers of macrophages, DCs and mast cells were revealed in both OSCCPP and OSCCBP groups. In conclusion, our findings revealed an association between the number of infiltrating cells and oral cancer prognosis. Moreover, our results suggest that the infiltrating cells (macrophages, Langerhans and mast cells) may be involved in the process of angiogenesis.