Estrogen receptors in the human male prostatic urethra and prostate in prostatic cancer and benign prostatic hyperplasia.

Estrogen receptors (ERs) in the prostate and prostatic urethra were examined in 33 men with benign prostatic hyperplasia (BPH) and in 11 with prostate cancer (PC). The Abbot monoclonal ER-ICA assay was used for immunohistochemical investigation. In the BPH group, ERs were revealed in the prostatic stroma in eight cases and in the glandular epithelium in one. In four cases ERs were seen in the prostatic stroma and in the glandular epithelium. In the prostatic urethra, ERs were found in 19 cases located in the urothelium, lamina propria and/or periurethral glands. In the PC group, ERs were demonstrated in the prostatic stroma and/or prostatic urethra in 6 out of 11 cases. In both BPH and PC patients, immunoreactivity was weak and confined to few cells, indicating low ER content in the prostate as well as in the prostatic urethra. Dextran-coated charcoal (DCC) analysis was used for detection and quanticization of cytosolic and nuclear ERs. In the BPH group, ERs were detected once in the prostate and prostatic urethra in the nuclear and cytosol, and additionally in the prostatic urethra in the cytosol fraction in three cases. In all cases, ER content was low, ranging from 10-15 fmol/mg protein. In the PC group, ERs were detected in the prostatic urethra and/or prostate in the cytosol fraction from two patients. The contents were low, ranging from 10-13 fmol/mg protein. We conclude that in human BPH and PC, ERs can be present in the prostate and prostatic urethra. In the prostate, ERs are mainly located in the stroma, but in BPH specimens they can also be found in the glandular epithelium. Biochemically, the use of the DCC analysis is of limited value, since ER content in the human prostate and prostatic urethra is at the limit of detection with this method.