INFLUENCE OF AN AROMATASE INHIBITOR ON BE NIGN PROSTATIC HYPERPLASIA (BPH)

It has been postulated that, beside androgens, estrogens may also play an important role in the pathogenesis of BPH. By aromatase inhibitors the formation of estrogens out of androgens can be inhibited selectiv ely and the effect of estrogen deprivation on BPH can be investigated for the first time. Within a phase II-study, men with a symptomatic BP H were treated with the aromatase inhibitor MADD (1-methyl-androsta-1, 4-diene-3,17-dione) (200 mg p.o. t.i.d.). After 3 months of treatment 4 patients with unchanged symptoms had an open prostatectomy and these BPH specimens were investigated histologically as well as immunohisto chemically. Results were compared to data obtained in the histologic s ections of 11 men with untreated BPH. After MADD-treatment, androgen-r eceptor concentration was lowered slightly in epithelial cells and ext ensively in stromal cells. In addition, it appeared that estrogen rece ptors were reduced after estrogen deprivation. On the other hand, in t hose MADD pretreated prostates the proliferation rate was higher in ep ithelium (0.200 % vs. 0.121 %) and slightly lower in stroma (0.095 vs. 0. 120 %) compared to untreated BPH. By morphometric assessment, howe ver, no difference was seen between both patient groups. In conclusion , the aromatase inhibitor-induced estrogen deprivation seems to have a n inhibitory influence on prostatic stroma and it may well be that BPH is affected via a suppression of androgen receptors. Whether or not t hese observed changes may cause an improvement of symptoms in BPH pati ents remains unclear, especially as the morphometric analysis did not reveal any differences between MADD-treated and untreated prostates.