The role of the lymphatic system and its specific growth factor, vascular endothelial growth factor C, for lymphogenic metastasis in prostate cancer

To compare prostate carcinoma, with and with no lymph node metastasis, to benign prostatic hyperplasia (BPH) tissue for lymphatic vessel density (LVD) and the expression of the lymph-endothelial specific growth factor, vascular endothelial growth factor C (VEGF-C), to determine their role in lymphogenic metastasis.

Lymphatic vessels were stained using lymphatic vessel endothelial hyaluronan receptor 1 and assessed in standard areas. The expression of VEGF-C was assessed by the number of positive epithelial cells. The data were compared with the clinical staging.

The lowest LVD was found in tumorous areas as opposed to periphery and nontumorous tissue (P = 0.007; P < 0.001). The highest LVD was in BPH tissue (P < 0.001). There was no correlation with clinical staging. There was more VEGF-C staining in pN1 than in pN0 and in BPH specimens (P = 0.002).

LVD is not a prognostic variable for the process of lymphogenic metastasis in prostate cancer. VEGF-C is up-regulated in prostate cancer and its correlation with lymph node status suggests a role for the development of lymph node metastasis, e.g. via an increased permeability of lymphatic vessels.