High-grade prostatic intraepithelial neoplasia in needle biopsy as risk factor for detection of adenocarcinoma: Current level of risk in screening population

Objectives. To assess the current incidence of prostate carcinoma detection in serial biopsies in a prostate-specific antigen-based screening population after a diagnosis of isolated high-grade prostatic intraepithelial neoplasia (HG-PIN) in needle biopsy tissue. Methods. We retrospectively identified 190 men with a diagnosis of isolated HG-PIN in needle biopsy tissue. Most men (86%) were diagnosed from 1996 to 2000. Logistic regression analysis was used to predict the presence of carcinoma in these 190 men and in a control group of 1677 men with only benign prostatic tissue in needle biopsy tissue. Results. The cumulative risk of detection of carcinoma on serial sextant follow-up biopsies was 30.5% for those with isolated HG-PIN compared with 26.2% for the control group (P = 0.2). Patient age (P = 0.03) and serum prostate-specific antigen level (P = 0.02) were significantly linked to the risk of cancer detection, but suspicious digital rectal examination findings (P = 0.1), the presence of HG-PIN (P = 0.2), and the histologic attributes of PIN were not (all with nonsignificant P values). HG-PIN found on the first repeat biopsy was associated with a 41% risk of subsequent detection of carcinoma compared with an 18% risk if benign prostatic tissue was found on the first repeat biopsy (P = 0.01). Conclusions. The results of our study have shown that the current level of risk for the detection of prostate carcinoma in a screened population is 30.5% after a diagnosis of isolated HG-PIN in a needle biopsy. This risk level is lower than the previously reported risk of 33% to 50%. HG-PIN is a risk factor for carcinoma detection only when found on consecutive sextant biopsies. The data presented here should prompt reconsideration of repeat biopsy strategies for HG-PIN, and re-evaluation of the absolute necessity of repeat biopsy for all patients with HG-PIN.