Expression Of Vascular Endothellal Growth Factor-C And Its Receptor VEGFR-3 In Hypopharyngeal Cancer Correlates With Lymph Node Metastasis

Objective: To investigate the relation between the expression of vascular endothelial growth factor-C (VEGF-C), its receptor VEGFR-3 and lymph metastasis in hypopharyngeal cancer.Methods: Immunohistochemistry methods and revert-transcription polymerase chain reaction (RT-PCR) were used to detect the expression of VEGF-C, VEGFR-3 in 46 cases of hypopharyngeal cancer(stage Ⅰ ,5; Ⅱ ,12; Ⅲ,17;Ⅳ,12) and 19 cases of normal hypopharyngeal mucosa .Results: The positive expression rate of VEGF-C, VEGFR-3mRNA in hypopharyngeal cancer and its lymphatic vessel endothelial cells was 63.04%, 71.74% respectively. The positive expression rate of normal mucosa epithelium was 21.05%, 36.84% respectively. The protein expression percent of VEGF-C in hypopharyngeal cancer is 58.69 %. The expression percent of normal mucosa epithelium is 21.05%. The expression percent of VEGFR-3 in vessel endothelial cells in hypopharyngeal cancer tissue is 14.59±7.36, The expression percent of normal mucosa epithelium is 8.24±5.83.There is positive correlation between VEGF-C in hypopharyngeal cancer tissue and VEGFR-3 in vessel endothelial cells of hypopharyngealcancer tissue. VEGF-C/ VEGFR-3 expression was more frequently found in tumors with lymph node metastasis than in those without it. VEGF-C expression in tumors and VEGFR-3 expression in vessel endothelial cells with lymphatic invasion were significantly greater than those in tumors without lymphatic invasion. The study showed significant correlation between VEGF-C and MVD in hypopharyngeal cancer tissue. No difference in age, stages and types between VEGF-C expression positive group and negative group. There was uncertainly difference in survival between VEGF-C expression positive group and negative group.Conclusions: In hypopharyngeal cancer, in paracrine fashion, VEGF-C may induce the proliferation of lymphatic vessels in the stroma of primary cancer via activation of VEGFR-3 and facilitates tumor metastasis via the lymphatic vessels. VEGF-C/ VEGFR-3 play an important role in lymph invasion/metastasis. In these circumstances, cancer cells can easily invade the lymphatic vessel, because of the increase of contact point of cancer cells with the lymphatic vessels. The overexpression of VEGF-C / VEGFR-3 may be helpful to prognosticate the frequency of regional lymph node metastasis and prognosis in hypopharyngeal cancer.