Immunohistochemical comparative analysis of cell proliferation and angiogenic index in squamous cell carcinomas of the tongue between young and older patients.

Oral squamous cell carcinoma (SCC) is a malignant epithelial tumor that is uncommon in individuals younger than 45 years. This study compared the cell proliferation and angiogenic index in SCCs of the tongue between young and older patients. Forty SCCs of the tongue, 20 diagnosed in young patients (≤ 40 y) and 20 diagnosed in older patients (>50 y) were evaluated by immunohistochemistry. Cell proliferation was evaluated using the Ki-67 labeling index (LI). The angiogenic index was determined by microvessel count (MVC) using anti- von Willebrand factor antibody. The mean Ki-67 LI in SCCs of the tongue was 43.8% (range, 26.0% to 72.4%) in young patients and 42.5% (range, 9.0% to 59.4%) in older patients (P=0.968). No significant difference in the Ki-67 LI was observed in relation to clinical stage or histologic grade of malignancy in either group (P>0.05). The mean MVC in SCCs of the tongue was 24.3 (range, 8.6 to 51.6) in young patients and 25.6 (range, 5.4 to 42.4) in older patients (P=0.543). There was no significant difference in MVC in relation to clinical stage or histologic grade of malignancy in either group (P>0.05). In addition, no significant correlation was observed between the Ki-67 LI and the angiogenic index (P>0.05). The results of this study suggest that the more aggressive biological behavior of SCC of the tongue in young patients may not be related to a higher cell proliferation rate or a higher angiogenic index.