Lymphatic Microvessel Density and the Expression of Lymphangiogenic Factors in Oral Squamous Cell Carcinoma

Objective: In this study, the expression of several lymphangiogenic growth factors was investigated to determine the mechanism underlying lymphangiogenesis in oral squamous cell carcinoma (OSCCa). Materials and Methods: An immunohistochemical study was performed to determine the lymphatic microvessel density (LMVD) and the expression of vascular endothelial growth factor (VEGF), plateletderived growth factor (PDGF), basic fibroblast growth factor (bFGF), insulin-like growth factors (IGF-I/II), and hepatocyte growth factor (HGF) in 25 OSCCa and 20 normal oral mucosal tissue samples. Results: Significantly higher levels of expression of VEGF, PDGF, bFGF, HGF, IGF-I, and IGF-II existed in OSCCa tissue compared to normal oral mucosal tissue (p 0.001, p 0.001, p 0.001, p,0.001, p , 0.001, and p 0.01, respectively; Mann-Whitney test). In OSCCa samples, significant positive correlations, based on the Spearman correlation test, existed between the LMVD and VEGF (r = 0.573; p 0.01), PDGF (r = 0.559; p 0.01), bFGF (r = 0.516; p 0.01), HGF (r = 0.448; p 0.05), and IGF-I (r = 0.6; p 0.01), but no correlation existed between LMVD and IGF-II (r = 0.380; p 1 0.05). Conclusion: These findings indicate that several growth factors may promote lymphangiogenesis in OSCCa. Future treatment for OSCCa utilizing antilymphangiogenic agents should target these different growth factor signaling pathways that are involved in lymphangiogenesis in OSCCa