ANDROGEN RECEPTOR CONTENT OF PROSTATE CARCINOMA-CELLS ESTIMATED BY IMMUNOHISTOCHEMISTRY IS RELATED TO PROGNOSIS OF PATIENTS WITH STAGE D2 PROSTATE CARCINOMA

BACKGROUND. Patients with prostate carcinoma generally respond to andr ogen withdrawal therapy, but subsequent progression to androgen-indepe ndence is frequently observed. Since androgen receptors play a key rol e in androgen action, the ratio of androgen receptor-containing cells in cancerous tissues was determined by immunohistochemical staining of prostate biopsy specimens for comparison with the outcome. METHODS. S ixty-two patients with untreated Stage D2 prostate carcinoma who recei ved endocrine therapy between 1986 and 1992 were included in the prese nt study. Biopsy tissue was stained with anti-human androgen receptor antibody, and the ratio of positively stained cells was estimated by c ounting 700 to 1000 cancer cells from each patient. Histologic grade, extent of bone metastases, clinical response to endocrine therapy, and outcome, were compared with androgen receptor-content. RESULTS. Cance rs with a low Gleason score had a significantly higher androgen recept or content than those with a high Gleason score, Androgen receptor con tent was not significantly correlated with extent of disease or tumor marker response at three months. Patients with 48% or more androgen re ceptor positive cells had a statistically significant better outcome, in terms of both progression free and cause-specific survival, than pa tients with less than 48% androgen receptor content. Multivariate anal ysis demonstrated that androgen receptor content, extent of disease, a nd tumor marker response at three months were significant predictors o f outcome. CONCLUSIONS. Androgen receptor content measured immunohisto chemically is a useful prognostic indicator for patients with Stage D2 prostate carcinoma treated with endocrine therapy. (C) 1996 American Cancer Society.