Is high grade prostatic intraepithelial neoplasia still a risk factor for adenocarcinoma in the era of extended biopsy sampling?

Abstract

There is controversy regarding the role of high grade prostatic intraepithelial neoplasia (HGPIN) on prostatic needle biopsy (PNB) as a risk factor for prostatic adenocarcinoma. We utilise a large Canadian database to determine whether HGPIN detected on extended PNB is a significant risk factor for prostatic adenocarcinoma. Pathological findings from PNBs from 12 304 men who underwent initial PNB during an 8 year period were analysed. Patients were included in the study if their initial diagnosis was HGPIN alone or a benign diagnosis, if at least one follow-up PNB was performed, and if both the initial and follow-up PNB contained at least 10 prostate cores. In the benign group of 105 patients and the HGPIN group of 120 patients, 14.1% and 20.8% were diagnosed with prostatic adenocarcinoma, respectively. When the HGPIN group was further subdivided into unifocal (1 core) and multifocal (>or=2 cores) groups, 9.4% and 29.9% developed prostatic adenocarcinoma, respectively (p < 0.0001). Cox regression analysis adjusting for age and prostate specific antigen (PSA) confirms the significance of HGPIN as a risk factor for prostatic adenocarcinoma (p = 0.0045). Patients with an initial diagnosis of multifocal HGPIN on extended PNB are at a greater risk for subsequent prostatic adenocarcinoma than those with unifocal HGPIN or benign diagnoses.