Androgen receptors in untreated and treated prostatic intraepithelial neoplasia.

Abstract

The effect of androgen deprivation therapy on the expression of androgen receptors (AR) and the proliferation-associated MIB-1 antigen in prostatic intraepithelial neoplasia (PIN) was investigated. Immunohistochemistry was performed on tissue sections of prostatectomy specimens of patients with prostate cancer who either were not treated prior to surgery or received androgen blockade therapy for 3 months. Immunohistochemistry on slides, selected for the presence of PIN was performed with an AR-specific monoclonal antibody and MIB-1 using a microwave antigen-retrieval method. AR expression was present in a majority of cells in PIN of both untreated and treated prostatectomy specimens. In addition, a proportion of normal prostatic glandular cells retained AR expression. The basal cells in both untreated and treated PIN did not express AR. MIB-1-positive cells were identified in PIN of untreated and treated cases. PIN lesions that persist after 3 months of androgen deprivation therapy continue to express AR and may therefore retain the potential to expand after cessation of this therapy.