Prostatic intraepithelial neoplasia and endocrine manipulation

Prostatic intraepithelial neoplasia (PIN) is the most common precursor lesion of prostatic adenocarcinoma. In 50- to 70-year-old participants of a randomized screening program for prostate cancer (Rotterdam section of the ERSPC) the frequency of high-grade PIN as an isolated finding in sextant prostatic needle biopsies was estimated to be about 1%. As yet, data in literature on the impact of androgen deprivation on PIN lesions are limited, showing discrepant outcomes. In part this may be the consequence of the application of different criteria for the identification of PIN under conditions of androgen deprivation. Foci of PIN could be distinguished in the majority of radical prostatectomy specimens of men treated for 3 or 6 months with combined endocrine therapy. Endocrine manipulation led to architectural changes (remodelling) in residual PIN which were more pronounced at 6 months of endocrine therapy. This is consistent with a prolonged effect of androgen deprivation on this precursor lesion. The presence of MIB-1 immunopositive nuclei in PIN lesions suggests that they still have the potential to expand after cessation of therapy.