Radioimmunoassay of tissue steroids in adenocarcinoma of the prostate.

Tissue steroid levels in 48 needle-biopsy samples of adenocarcinoma of the prostate were quantified by radioimmunoassay (RIA). Tissue levels of dihydrotestosterone (DHT), estradiol-17 beta, and estrone were correlated with the tumor stage, histologic grade, and patient response to endocrine therapy. All patients with well-differentiated carcinoma of the prostate had tissue DHT content greater than 2.0 ng/g while 35% of patients with moderately differentiated or poorly differentiated tumors had tissue DHT content less than 2.0 ng/g. DHT content appeared to be unrelated to tumor stage. Estradiol and estrone content correlated well with tumor grade but not with tumor stage. DHT levels were measured in 17 patients with symptomatic Stage D2 carcinoma of the prostate. Thirteen patients with DHT content greater than 2.0 ng/g initially had an objective and/or subjective response to endocrine therapy. Four patients with tissue DHT levels below 2.0 ng/g had no response to hormonal therapy. Quantification of tissue DHT content by RIA is a promising method for predicting initial response to hormonal therapy in adenocarcinoma of the prostate.