Lymphangiogenesis and Angiogenesis in Bladder Cancer: Prognostic Implications and Regulation by Vascular Endothelial Growth Factors-A, -C, and -D

Abstract

Lymph vessel density (LVD) and microvessel density (MVD) correlate with the malignant potential of tumors and patient survival. Vascular endothelial growth factors (VEGF)-A, VEGF-C, and VEGF-D could modulate LVD and MVD. We investigated the clinical and prognostic significance of LVD and MVD on lymphangiogenic and angiogenic function of VEGF-A, VEGF-C, and VEGF-D in human bladder cancer. We reviewed tissue samples from patients with nonmetastatic bladder cancer who had undergone transurethral resections (n = 126). The densities of D2-40-positive vessels (LVD) and CD34-positive vessels (MVD) were measured by a computer-aided image analysis system. Expression of VEGF-A, VEGF-C, and VEGF-D was examined by immunohistochemistry; survival analyses and their independent roles were investigated using multivariate analysis models. LVD was associated with tumor grade but not with pT stage. LVD was associated with metastasis-free survival (log rank P = 0.039), but was not an independent prognostic factor. Although MVD affected survival, the combination of high LVD and high MVD in tumors was an independent predictor of metastasis-free survival. Although VEGF-C expression was positively associated with both LVD and MVD, VEGF-D was associated only with LVD. VEGF-A expression was associated with MVD in univariate analysis, however, it was not an independent factor. Lymphangiogenesis and angiogenesis influence metastasis-free survival, and are regulated by VEGF-C and/or VEGF-D. Our results suggest that LVD and MVD are useful tools for the selection of postoperative management and treatment strategies in patients with bladder cancer.