In 24 untreated stage D2 prostate cancer patients with prostate DHT levels greater than 2.5 ng/g, 20 initially responded to therapy with partial objective progression (POR) or were objectively stable (OS) for 12 or more months while four patients relapsed in less than 1 year. Of eight patients with prostate DHT levels less than 2.0 ng/g, five had either objective progression or were objectively stable for 6 months or less; two other patients have completed remissions ranging from 16 to 24 months while one patient remains objectively stable for 21 months to date. DHT concentrations were also measured in prostate tissue of patients with advanced prostate cancer in relapse following either DES or castration with or without estrogen therapy. Although castration, medical or surgical, usually leads to DHT concentrations of less than 2.4 ng/g, two out of 20 surgical castrates and four out of nine estrogen-treated patients had values above this level. These differences suggest that (1) increased tissue DHT levels of DES-treated patients may be due to inadequate dosage or decreased compliance, and (2) increased tissue DHT concentrations greater than 2.4 ng/g in castrates suggests an adrenal cortical androgen contribution to the prostate DHT level. These studies suggest that DHT measurements in prostate cancer tissue are of value in predicting response in untreated prostate cancer patients and of directing therapy in patients who are in relapse after orchiectomy or estrogen therapy.
Castration Diethylstilbestrol