Objectives: Lymphangiogenesis is associated with tumor progression in various cancers and is regulated by vascular endothelial growth factors (VEGFs). However, little is known about the pathologic roles of lymphangiogenesis in renal cell carcinoma (RCC). We investigated the relationships between various clinicopathologic features and lymphangiogenesis, angiogenesis, and expression of VEGFs in RCC.
Methods: The TNM stage and grade of 107 conventional RCC were reviewed. Lymph vessel density (LVD) and microvessel density (MVD) were measured by quantitative immunohistochemistry using anti-D2-40 antibody and anti-CD34 antibody, respectively. Expression levels of VEGF-A, B, C, and D were examined by immunostaining.
Results: D2-40-positive lymphatic vessels were detected mainly in the peritumoral area. However, no significant difference was found between LVD in peritumoral areas of the RCC tissues and the normal kidney (P = 0.238). Intratumoral D2-40-positive lymphatic vessels were detected in only six specimens, and neither intratumoral nor peritumoral LVD correlated with the clinicopathologic features. VEGF-A expression correlated with MVD (r = 0.50, P <0.001), but not with LVD, and was also associated with pT stage, the presence of metastasis, and tumor grade. No other members of the VEGF family showed any correlation with LVD, MVD, or the clinicopathologic features.
Conclusions: Lymphangiogenesis seems to play a minimal role in the progression of human RCC. Only VEGF-A, but not B, C, or D, was associated with the histopathologic features and MVD of RCC.