Prostatic intraepithelial neoplasia: a risk factor for prostate cancer.

Prostatic Intraepithelial Neoplasia (PIN) is an increasingly common finding at ultrasound guided prostate biopsy, with the high grade form (HGPIN) thought to be "precancerous". With the more widespread use of extended biopsy protocols, taking sometimes up to 14 cores or more, the incidence of HGPIN can be up to 25%. Histologically, it has many features in common with cancer of the prostate and has been shown to be both associated with cancer at the time of its finding and predictive for the development of prostate cancer in the future. Basic science research has demonstrated genes common specifically to both prostate cancer and HGPIN and immunostaining studies of microvessel density may help to differentiate HGPIN from lower risk PIN. There are no active treatments for HGPIN although there are trials to assess the effectiveness of hormonal therapy and nutritional supplements. Currently most urologists recommend that patients should be followed at 6 monthly intervals with regular PSA and repeat biopsies as indicated.