Vascularization influences tumor development by supporting the nutrition and dissemination of tumor cells. On the other hand, a low number of vascular vessels (VVlow) may induce hypoxia, accounting for selection of resistant clone(s) of tumor cells. This study aimed to evaluate the prognostic significance of vascular (VV) and lymphatic vessels (LV) in prostate cancer (PCa). Tumor samples from 400 PCa patients undergoing radical prostatectomy (RP) were prepared in duplex as tissue microarrays. Numbers of VV and LV were evaluated using immunohistochemistry detecting CD34 and podoplanin, respectively, and correlated to clinical data, biochemical recurrence (BR), and proteins analyzed in tumor cells. VVlow and LV were found in 32% and 43% of patients with informative PCa samples, respectively. VVlow correlated with a shorter time to BR 3, 5, and 10 years after RP in hormone-naïve patients (p = 0.028, p = 0.027 and p = 0.056, respectively). It was also shown to be an independent prognostic factor 5 years after surgery (multivariate analysis, p = 0.046). Tumors characterized by VVlow expressed the epithelial cell adhesion molecule, EpCAM, less frequently (p = 0.016) and revealed a borderline correlation to increased levels of tumor cell invasion marker Loxl-2 (p = 0.059). No correlations were found for LV. In summary, VVlow in hormone-naïve patients undergoing RP has prognostic potential and seems to be related to an aggressive phenotype of tumor cells.
Keywords: CD34; heterogeneity; hormone-naïve patients; lymphatic vessels; podoplanin; prostate cancer; tumor progression; vascular vessels.