CLINICAL PROGNOSTIC CRITERIA FOR LATER DIAGNOSIS OF PROSTATE CARCINOMA IN PATIENTS WITH INITIAL ISOLATED PROSTATIC INTRAEPITHELIAL NEOPLASIA

Prostatic intraepithelial neoplasia (PIN) is considered as a precursor of prostate cancer and is frequently associated with it. Diagnosis of PIN on a prostate needle biopsy without associated carcinoma is a dif ficult problem since high-grade PIN does not necessarily mean that pro state cancer is always present and low-grade PIN is associated with ca ncer as well. Definition of parameters predictive of the later finding of prostate cancer on repeat biopsy in patients with PIN is of eviden t interest and we have reviewed our experience and recent data from th e literature on this topic. High grade is a strong predictor of later cancer found on repeat biopsy (50-100%) and in these patients, serum p rostate-specific antigen (PSA), digital rectal examination and transre ctal ultrasound are predictors of later cancer found on repeat biopsy. High-grade PIN is, however, frequently associated with later cancer w hatever PSA, even when less than or equal to 4 ng/ml. Low-grade PIN se ems to behave like BPH since the incidence of later cancer is extremel y low when PSA is <4 ng/ml and is high when PSA >10 ng/ml. Patients wi th high-grade PIN should systematically be rebiopsied after 3-6 months to exclude cancer because they are likely to have undiagnosed cancer. Patients with low-grade PIN and low PSA seem to have a low risk of la ter cancer found on repeat biopsy. Patients with low-grade PIN and hig h serum PSA should have repeat biopsies because the incidence of subse quent cancer is high and comparable to high-grade PIN. Further investi gations are needed to optimize the management of patients with low-gra de PIN and intermediate PSA level.