Topography of neovascularity in human prostate carcinoma

All neoplasms require angiogenesis and resulting neovascularity for growth. The authors and others have confirmed the staging and prognostic significance of quantitative microvascularity density (MVD) in human prostate carcinoma (CAP). In the present investigation, the authors sought to identify the specific site of neovascularity within the neoplasm and adjacent benign tissue.

Histologically benign and malignant tissues from 14 random radical prostatectomy specimens were studied. The tumor edge was defined precisely by immunohistochemistry, suggesting a high molecular weight cytokeratin that stains only the basal cells of benign histology. Microvascularity density quantification was performed using von Willebrand factor antigen immunohistochemistry as previously defined. Five parallel arcs were defined along which vessel density was calculated including arcs within, on the edge, and removed from the neoplasm.

In 13 of 14 cases, the highest vessel density was found within the tumor. Significant differences were observed between the edge of the tumor and 2.5 mm within the benign periphery, between the benign and malignant tissue at the border, and between CAP at the edge and CAP 2.0 mm within the neoplasm. These findings suggest a stepwise increase in MVD toward the center of the neoplasm.

These data confirm the authors' previous observation that prostate cancer has approximately a two-fold increase in MVD compared with the benign tissue. Moreover, high vascularization of the center explains the rare finding of necrosis in CAP. These data suggest that angiogenic promoters may have their highest activity in the center of the neoplasm.