Which play a more important role in the development of large-sized prostates (≥80 ml), androgen receptors or oestrogen receptors? A comparative study.

OBJECTIVE: To compare the expression levels of androgen receptor (AR), oestrogen receptor α (ERα)and oestrogen receptor β (ERβ) in human prostate with various degrees of benign hyperplasia.
MATERIALS AND METHODS: Forty-five BPH patients undergoing transurethral plasmakinetic resection of the prostate were divided into three 15-people groups of participants with small (<40 ml), medium (40-80 ml) and large (>80 ml) prostates. Patient blood samples were collected for measuring serum oestradiol (E2), total testosterone (TT), follicle-stimulating and luteinizing hormone by radioimmunoassay. Postoperative prostate specimens were collected to detect AR, ERα and ERβ expression by immunoblotting and immunohistochemical staining.
RESULTS: There were significantly lower serum E2 levels in the patients with large prostates compared to the patients with small prostates (P < 0.05) and medium prostates (P < 0.01). A high TT and E2 serum ratio was observed in patients with large-sized prostates (P < 0.05), but there were no obvious differences in the serum TT levels between the three groups. Prostate AR expression in patients with large- (P < 0.05) and medium-sized prostates (P < 0.01) was high compared to patients with small-sized prostates. Prostate ERα expression in patients with large prostates was low compared to patients with small- and medium-sized prostates (P < 0.01). The prostate ERβ expression did not differ between the three groups (P > 0.05).
CONCLUSIONS: Increased AR and decreased ERα expression in the prostate suggested that AR might be more important than ERα in stimulating prostate proliferation in patients with large-sized prostates. Patients with small- and large-sized prostates might require different management procedures involving selective oestrogen receptor modulators and selective androgen receptor modulators, respectively.