ERG positive prostatic cancer may show a more angiogenetic phenotype.

In Western populations, roughly half of prostatic carcinoma (PC) cases show translocations involving the ETS transcription factor family genes and overexpression of the ERG transcription factor. ETS transcription factor family is known to be involved in angiogenesis. Microvascular density (MVD) influences the prognosis of various solid tumors, yet its significance in PC remains unclear. The aim of the study was to analyze microvascular density in prostatic adenocarcinoma in relationship to ERG expression. This is a retrospective study of 112 cases whose aim is to compare MVD in ERG-positive and negative cases and to test its relationship with other pathological parameters. Immunohistochemical stains for ERG and CD31 were done using standard methods, using tissue microarrays. The cases were classified as ERG-positive and negative and the CD31-positive vessels were counted. Fifty-one cases (45.54%) were positive for ERG, and the average MVD was 111.81 vessels/mm(2) (standard deviation, SD 54.20) for the entire group, 101.30 vessels/mm(2) (SD 50.60) for ERG-negative and 124.38 vessels/mm(2) (SD 56.17) for ERG-positive cases. There was only a slight tendency for higher MVD in higher grades and stages of cancer. None of other parameters, such as patients' age, lymphovascular invasion, presence of intraductal carcinoma or positive surgical margin, showed a significant relationship to MVD. This shows for the first time that ERG expression and MVD may have a significant relationship in prostatic adenocarcinoma.