Histological localization of estrogen receptors in normal and diseased human prostates by immunocytochemistry.

The role of estrogens and estrogen receptors (ER) in the human prostate remains unresolved. In this study we have used the monoclonal ER antibody H222 to investigate the histological localization of ER in normal and diseased human prostates by immunocytochemistry. Prostate tissue was obtained from 3 young organ donors (Group I-normal prostate), from 14 prostates removed by radical prostatectomy or radical cystoprostatectomy, which had caused no or only mild obstructive symptoms (Group II-non-obstructive prostate), and from 11 prostates removed by suprapubic prostatectomy, which had caused severe obstructive symptoms due to a large benign prostatic hyperplasia (BPH) (Group III-obstructive prostate). In prostates of all groups ER were found to be in nuclei of the prostatic urethra and of the periurethral prostatic duct. In striking contrast, ER in the interglandular prostatic stroma was not as homogeneous among the different groups. We observed a low concentration of ER in the stroma of normal prostates, the highest concentration in non-malignant stroma of non-obstructive prostates, and no ER at all in stroma of obstructive prostates. Based on the immunocytochemical localization of ER in normal and diseased human prostate, our results indicate that stromal growth in obstructive BPH may not be mediated via ER. However, we cannot exclude that an increase of stromal ER concentration (as observed in non-obstructive prostates) is directly involved in induction of BPH, leading further prostate growth thereafter into an estrogen independent state.