Steroid receptor content in human prostatic carcinoma and response to endocrine therapy

Biopsy material from primary prostatic carcinoma from 25 patients was analyzed with regard to cytosol content of methyltrienolone (a synthetic androgen) binding sites and the receptor content has been correlated to the clinical response to endocrine therapy. A dextran-coated charcoal technique was used and binding data were calculated from Scatchard plots. In 20 of the tumors detectable levels of methyltrienolone receptor were noted. One of the receptor-positive patients died during radiation therapy before onset of hormonal treatment, and a second patient, who had a highly differentiated carcinoma, so far has not received any endocrine therapy. Of the remaining 18 patients 15 responded well to castration, treatment with estrogens, or Estracyt (approximately 80%). The biopsies from two of the three receptor-positive non-responders contained the lowest measurable receptor levels. Five specimens lacked detectable amounts of methyltrienolone receptor. Four of these patients did not respond to therapy (approximately 80%), but one was "false" negative. Our data indicate that steroid receptor analysis may become an important tool in predicting the value of endocrine therapy in human prostatic carcinoma.