Objectives: Prostatic intraepithelial neoplasia (PIN) is considered the most likely precursor of prostatic adenocarcinoma. The effect of androgen deprivation therapy on the prevalence of PIN is unknown.
Methods: We undertook a case-control study of radical retropubic prostatectomies from 24 treated patients and a control group of 24 untreated patients matched for age and clinical stage (all T3). Androgen deprivation therapy included LHRH agonist leuprolide and flutamide (18 patients), diethylstilbestrol (DES) (2 patients), DES with leuprolide and flutamide (1 patients), and orchiectomy (3 patients). Prostatectomy specimens were evaluated for the presence and extent of high-grade PIN according to the number of high-power microscopic fields, and nuclear tumor grade (1 to 4 scale) and Gleason score were also determined.
Results: The prevalence of high-grade PIN in pretreatment transrectal needle biopsies was similar in the treated and untreated groups. The prevalence and extent of high-grade PIN were lower in cases treated with androgen deprivation therapy than controls. Nuclear tumor grade was also lower in treated patients, but there was a paradoxical increase in the Gleason score. The prevalence of aneuploidy in the cancers was similar in both groups.
Conclusions: These findings suggest that androgen deprivation therapy decreases the prevalence and extent of high-grade PIN.