Intraprostatic testosterone and dihydrotestosterone. Part II: concentrations after androgen hormonal manipulation in men with benign prostatic hyperplasia and prostate cancer.

Androgen deprivation therapy (ADT) and 5-α-reductase (5AR) inhibition are used in the treatment of men with advanced or metastatic prostate cancer and benign prostatic hyperplasia (BPH), respectively. These drugs exert their effect by lowering androgen levels in the serum and allegedly, the prostate gland. It is, however, unknown whether (increased) intraprostatic androgen levels are associated with the pathogenesis of BPH and with the initiation and progression of prostate cancer. Also, it is unclear whether intraprostatic dihydrotestosterone (DHT) levels correlate with a response to initial hormonal therapy or with patient outcome. These uncertainties have resulted from the finding that serum testosterone levels do not necessarily reflect those in the prostate gland. Intraprostatic DHT levels of men being treated with 5AR inhibition, of those treated with ADT for hormone-naive prostate cancer, and of those with castration-resistant prostate cancer are all altered in an equivalent manner because of hormonal manipulation. Increased knowledge of the mechanisms of the androgenic steroid pathways in prostatic diseases, with a special focus on intraprostatic androgen levels, may lead to treatment that is tailored to the needs of the individual patient, and probably to new therapeutic targets as well.