Metastasis in head neck cancer can occur by local infiltration, lymphatic and hematogenous route.
VEGF has been implicated as one of the factor for angiogenesis which aids in dissemination of tumour cells from primary to a distant site.
Aims and objectives
To compare VEGF expression in non malignant (stratified squamous epithelium overlying pyogenic granuloma), premalignant lesion (leukoplakia) and SCC of oral cavity and further to evaluate expression in relation to grade of the tumour.
Material and methods
Immunohistochemical expression of VEGF in 90 cases of oral SCC [30 cases each of well differentiated (WD), moderately differentiated (MD) and poorly differentiated (PD) carcinoma] and 30 cases each of leukoplakia and pyogenic granuloma evaluated.
VEGF expression observed as brown intracytoplasmic staining and was counted in tumour cells on basis of intensity and percentage positivity and expressed as VEGF score. VEGF grade was also calculated.
Result
The VEGF score in WD SCC was maximum with VEGF grade 3. The VEGF grade in MD SCC was less than WD SCC but more than PD SCC, with VEGF grade 2 in MD SCC and VEGF grade 1 in PD SCC . VEGF score and VEGF grade in leukoplakia and epithelium overlying pyogenic granuloma were similar but less than that of WD & MD SCC. VEGF grade of PD SCC was similar to leukoplakia & epithelium overlying pyogenic granuloma.
Conclusion
We observed significant decrease in VEGF expression as the degree of differentiation declined in oral SCC with poorly differentiated tumors demonstrating negligible VEGF expression. There is controversy in literature regarding the expression of VEGF in relation to the grade of the tumor. It is speculated that vascular proliferation in poorly differentiated SCC occurs through a different mechanism.