Association of Stromal Factors With the Histologic Risk Assessment Model in Oral Squamous Cell Carcinoma

The aim of the present study was to evaluate angiogenesis, lymphangiogenesis, and mast cell density in association with the histologic risk assessment (HRA) model in oral squamous cell carcinoma. One hundred oral squamous cell carcinomas were graded according to the HRA system and immunostained with antibodies against D2-40, CD34, and CD105 to determine lymphvessel density (LVD) and microvessel density (MVD). Mast cells were detected by toluidine blue and counted in all samples. Assessments were made between the evaluated factors and the histologic variables of HRA. Kruskal-Wallis and Mann-Whitney U test were used for statistical analysis and P<0.05 was considered significant. There were 32, 26, and 42 cases of low, intermediate, and high-grade neoplasms, respectively. Only LVD (P=0.05) and CD34MVD (P=0.03) showed significant associations with lymphocytic infiltration and were both higher in score 0 cases compared with score 3 tumors (P=0.05 and <0.001, respectively). None of the other variables showed significant relationships with the HRA risk scores or subcategories (P>0.05). According to our findings, it appears that the role of lymphangiogenesis and angiogenesis is limited in the HRA system. The significant relationship of lymphocytic infiltration with LVD and CD34MVD, but not CD105MVD, might indicate that "inflammatory lymphangiogenesis/angiogenesis" may differ from that induced by noninflamed neoplastic tissues. It also seems that the vasculature in inflamed tumor tissues is not entirely newly formed.