Background & objective: Recently, vascular endothelial growth factor-C (VEGF-C) and -D (VEGF-D) have been identified as specific lymphangiogenic factors, and their overexpression are related to lymphatic metastasis. This study was to investigate the expression and clinical significance of VEGF-C and VEGF-D in nasopharyngeal carcinoma (NPC).
Methods: The expression of VEGF-C, VEGF-D, vascular endothelial growth factor receptor-3 (VEGFR-3), and CD34 in 66 specimens of NPC and 19 specimens of nasopharyngitis tissue were detected by SP immunohistochemistry. Lymphatic microvessel density (LMVD) and microvessel density (MVD) were calculated.
Results: The high expression rate of VEGF-C was significantly higher in NPC than in nasopharyngitis tissues (54.5% vs. 26.3%, P<0.05). The high expression rate of VEGF-C was significantly higher in the NPC with regional lymph node metastasis than in those without, and higher in the NPC with high T stage than in those with low T stage (P<0.05). Both univariate and multivariate logistic regression analyses showed that high expression of VEGF-C was correlated to regional lymph node metastasis (P<0.05), but not to age, sex, 5-year survival, LMVD, and MVD (P>0.05). The positive rate of VEGF-D was significantly higher in NPC tissues than in adjacent non-cancerous tissues (69.7% vs. 42.1%, P<0.05). In NPC tissues, VEGF-D expression had no correlations to age, sex, T stage, regional lymph node metastasis, LMVD, and MVD (P>0.05), but was positively related to high expression of VEGF-C. The 5-year survival rate was significantly lower in VEGF-D-positive NPC than in VEGF-D-negative NPC (50.0% vs. 85.0%, P<0.05).
Conclusion: In NPC, high expression of VEGF-C is closely correlated to regional lymph node metastasis; positive expression of VEGF-D shows no correlation to regional lymph node metastasis, but is positively related to high expression of VEGF-C and closely correlated to 5-year survival rate.