Extent of high-grade prostatic intraepithelial neoplasia is not a predictor of cancer at repeat biopsy

Objective : High-grade prostatic intraepithelial neoplasia (PIN) is a well accepted pre-cursor of invasive prostate cancer. Most investigators agree that a diagnosis of high-grade PIN warrants repeat transrectal ultrasound guided biopsy. We set out to investigate risk factors for cancer among a modern cohort of men with isolated high-grade PIN. Material and Methods : The Princess Margaret Hospital has a comprehensive database of 6249 TRUS procedures over the past 8 years. We searched this dataset for the following parameters: a) diagnosis of high-grade PIN between 1997 and 2003; b) absence of atypia or cancer and c) repeat prostate biopsy to rule out cancer. Addi-tional covariates assessed were: age, pro-state specific antigen (PSA) level at the time of biopsy, digital rectal examination (DRE) findings, transrectal ultrasound (TRUS) stage, TRUS volume, and the amount of PIN at biopsy (defined as one core vs. greater than one core by review of pathology reports). All data were tabulated and univariate (chi-square/t-tests) as well as multivariate (logistic regression) analyses were performed. All significance testing was two-sided with p Results : A total of 130 patients had a diagnosis of high-grade PIN and underwent repeat biopsy. Among this cohort, 41 patients (31.5%) had cancer at re-biopsy.The Gleason sum distribution for these tumors was: 6 in 32 patients, 7 in 8 patients and 9 in 1 patient. Among the entire cohort the mean age was 64.1 years (range 37-78); PSA was 8.3 ng/ml (range: 0.28-70.2); and prostate volume was 65.43 cc (range 16-182.9). Fifteen patients (11.5%) had abnormal DRE, 53 (40.8%) had hypo-echoic lesions at TRUS, and 46 (35.4%) had more than one core high-grade PIN. On uni-variate analysis, the presence of an abnormal TRUS (22 of 52 with hypo-echoic lesions vs. 19 of 76 without hypo-echoic lesions, p=0.039) and the prostate volume (mean volume 69.66 cc for benign re-biopsies versus 56.89 cc for positive repeat biopsies, p 6) and the extent of PIN at first biopsy (p=0.86). Conclusions : In a modern cohort of men with high-grade PIN, PSA, DRE and age are not predictive of cancer at re-biopsy. There was no association between Gleason score at biopsy (6 vs > 6) and the extent of PIN at first biopsy. The prostate volume was the only significant predictor of cancer at re-biopsy. Resume Objectifs : La neoplasie intra-epitheliale prostatique de haut grade (PIN) est un precurseur bien connu de cancer de la prostate invasif. La plupart des investigateurs consentent qu'un diagnostic de PIN de haut grade justifie la repetition des biopsies transrectales echo-guidees. Nous avons eu l'intention d'enqueter sur les facteurs de risque pour cancer parmi une cohorte moderne d'hommes avec haut grade de PIN. Patients et methodes : L'Hopital de la Princesse Margaret a une base de donnees complete de 6249 procedures de TRUS sur les 8 annees passees. Nous avons cherche ce dataset avec les criteres d'inclusion suivants : a) diagnostic de PIN de haut grade entre 1997 et 2003; b) absence d'atypies ou cancer et c) biopsie repetee de la prostate eliminant le cancer. Les covariantes supplementaires etaient: l'âge, l'antigene specifique de la prostate (PSA) au moment des biopsies, les conclusions du toucher rectal (DRE), la TRUS, le volume a la TRUS, et le taux de PIN aux biopsies (defini comme focal ou plus que focal lors de la revision des rapports de la pathologie). Toutes les donnees ont ete disposees en tableau et des analyses univariees (tests chi square/t) et multivariees ont ete realisees. Resultats : Un total de 130 patients avait un diagnostic de PIN de haut grade et ayant subi une deuxieme serie de biopsies. Parmi cette cohorte, 41 patients (31.5%) avaient le cancer a la re-biopsie. Les scores de Gleason pour ces tumeurs etaient: 6 chez 32 patients; 7 chez 8 patients et 9 chez 1 patient. Parmi la cohorte entiere l'âge moyen etait 64.1 annees (37-78 ans); la PSA etait de 8.3 (0.28-70.2); et le volume de la prostate etait de 65.43 grammes (16-182.9). Quinze patients (11.5%) avaient un DRE anormal, 53 patients (40.8%) avaient des lesions l'hypo-echogenes a la TRUS, et 46 (35.4%) avaient un PIN de haut grade plus que focal. Sur l'analyse univariee, la presence d'un TRUS anormal (22 de 52 avec lesions hypo-echogenes contre 19 de 76 sans lesions, p = 0.039) et le volume de la prostate (volume 69.66 moyen pour re-biopsies benignes contre 56.89 pour les biopsies repetees positives, p 6) et l'importance du PIN a la premiere biopsie (p=0.86). Conclusions : Dans une cohorte moderne de patients avec PIN de haut grade, PSA, DRE et âge ne sont pas predictifs de cancer a la re-biopsie. Il n'y avait aucune association entre le score de Gleason, la re-biopsie (6 contre> 6) et l'importance du PIN a la premiere biopsie. Le volume de la prostate etait le seul facteur predictif de cancer a la re-biopsie. African Journal of Urology Vol. 12(1) 2006: 10-14