Role of estrogens in human benign prostatic hyperplasia

The aging process is associated with a progressive decline of plasma testos terone levels, while estrone and estradiol remain unchanged and sex hormone binding globulin (SHBG) increases, with reduction of bioavailable testoste rone in prostatic tissue with benign prostatic hyperplasia (BPH) the most i mportant androgen is dihydrotestosterone: with its receptors it is almost u niformly distributed in the epithelial and stromal compartment and is not s upranormal. Intraprostatic estrogens and their receptors are elevated and c oncentrated in the stroma. Androgens may act on the prostate indirectly thr ough the production of growth factors; in human BPH no clear evidence exist s on the modulatory effect of estrogens on bFGF, KGF and TGF beta formation . A western diet, characterized by high fat consumption, predisposes men to BPH, while a diet rich in flavonoids and lignanes, containing phyto-estrog ens, lowers this risk. These data suggest that in the medical treatment of BPH, antiestrogens or aromatase inhibitors may be used: however, up to now the clinical results of this treatment are not promising and the improvemen t of the obstructive symptoms does not exceed that of placebo. A possible e xplanation of this unsatisfactory result could be that the estrogen reducti on secondary to the use of aromatase inhibitors is counterbalanced by the r ise of androgen precursors.