Vascular Endothelial Growth Factor Expression And Micro-vessel Density In Oral Squamous Cell Carcinoma And Their Relation To Clinicopathologic Features And Prognosis

Objective: Angiogenesis is essential for solid tumor growth. It has been suggested that angiogenesis is an early event in tumorrigenesis and may facilitate tumor progression , metastasis and recurrence. Tumor angiogenesis may be regulated by some growth factors that are secreted by tumor cells. Vascular endothelial growth factor(VEGF) is a recently discovered mitogen for endothelial cells and a potent angiogenesis-promoting factor, and it is thought to be a major tumor angiogenesis regulator. With regard to its role in oral carcinoma,there have been a few studies regarding the association between VEGF expression and angiogenesis. This study examined VEGF expression and microvessel density in oral squamous cell carcinomas to clarify the relationship between VEGF expression and angiogenesis , the clinicopathologic features and prognosis of the disease.Materials and Methods: All tissues samples were taken from 56 patients with oral squamous cell carcinoma(OSCC) after surgery in the Oral and Maxillofacial Surgery Department of Taian City Central Hospital from 1984 to 1996 .The pathologic review was performed to described the degree of differentiation and invasion.The clinicopathologic stage was based on thestandard of UICC .The follow-up survey for all the cases were performed after the operation. All specimens were fixed by formalin, embeded in paraffin wax,and examined in 5 microns sections by means of SABC methods. VEGF expression in these OSCCs was examined immunohistochemically. Microvessels in the tumor stained for Factor Vffl-related antigen were counted.Results: VEGF expression was observed in 29 of the patients (51. 8%) .Themicrovessel count was significantly higher (p<0.05) in the OSCC with VEGF expression than in the OSCC without it. In the clinicopathologic factors, lymph node metastasis(p<0.05) and differentiated degree (p<0.05) were significantly correlated with VEGF expression, but there was no significantly correlation between the clinicopathologic stage and VEGF positive expression. The 5-year survival rate after curative surgery was better in the patients without VEGF expression (p<0.05). There were significantly correlation between the lymph node metastasis(p<0.05) -. differentiated degree (p<0.05)^ clinicopathologic stage and highter MVD count. The 5-year survival rate after curative surgery was better in the patients with lower MVD count (p<0.05).Conclusions: This study indicates that VEGF expression is associated with angiogenesis, and is positively correlated with the occurrence, progression and lymphatic invasion of OSCCs. VEGF is one of the main angiogenic factors for OSCC, and is able to induce tumor angiogenesis and accelerate tumor growth. Quantification of VEGF and MVD in oral tissues may provide a valuable marker for a prognosis of patients with OSCCs,and conduct biological treatment.