Correlation between neovascularisation and neuroendocrine differentiation in prostatic carcinoma

Neuroendocrine (NE) differentiated tumor cells are found in almost all prostatic carcinomas. Prostatic carcinomas with a high NE differentiation have a poor prognosis and increased metastatic potential. A relationship between the neovascularisation density in the tumor and the metastatic potential in prostatic carcinoma is well known. NE cells and microvessels were demonstrated immunohistochemically on 102 radical prostatectomy specimens using antibodies against Chromogranin A and CD34. Standard areas (7.9 mm2) of maximal Chromogranin A expression and highest vascularisation were determined and topographically related by light microscopy. Area density of microvessels was evaluated morphometrically. NE tumor cells were present in all prostatic carcinomas studied. High grade prostatic carcinomas expressed significantly more NE tumor cells and exhibited a higher neovascularisation than low grade carcinomas. There was significantly higher neovascularisation in high grade tumors with many, as compared to high grade tumors with few, NE tumor cells. Poorer pathological staging correlated with increased neovascularisation and stronger NE differentiation. A topographical relationship between the area of maximal NE tumor cells and the area of highest neovascularisation was found in 80.4% of all cases. An analysis of variance revealed a large number of NE tumor cells as the only predictor of an increased neovascularisation (p = 0.0006). These observations support the concept that increased neovascularisation is influenced not only by poor pathological grading but also by a high NE differentiation.