Background: Age-dependent increase in the incidence of benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are both related to cell proliferation and survival controlled by intraprostatic free testosterone (FT) concentration. Paradoxically, BPH and PCa occur as circulating testosterone levels decrease, so any possible relationship between testosterone levels and development of BPH and PCa remains obscure.
Results: In BPH the enlarging prostate is exposed to high testosterone levels arriving directly from the testes at concentrations about hundredfold higher than systemic FT.