MP49-12 HETEROGENEITY OF ERG EXPRESSION IN PROSTATE CANCER: A LARGE SECTION MAPPING STUDY OF ENTIRE PROSTATECTOMY SPECIMENS FROM 115 PATIENTS

Abstract

You have accessJournal of UrologyProstate Cancer: Basic Research IV1 Apr 2014MP49-12 HETEROGENEITY OF ERG EXPRESSION IN PROSTATE CANCER: A LARGE SECTION MAPPING STUDY OF ENTIRE PROSTATECTOMY SPECIMENS FROM 115 PATIENTS Meike Adam, Christina Maria Tsourlakis, Annegret Stender, Ronald Simon, Hans Heinzer, Guido Sauter, Sarah Minner, and Thorsten Schlomm Meike AdamMeike Adam More articles by this author , Christina Maria TsourlakisChristina Maria Tsourlakis More articles by this author , Annegret StenderAnnegret Stender More articles by this author , Ronald SimonRonald Simon More articles by this author , Hans HeinzerHans Heinzer More articles by this author , Guido SauterGuido Sauter More articles by this author , Sarah MinnerSarah Minner More articles by this author , and Thorsten SchlommThorsten Schlomm More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1113AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives Chromosomal rearrangements leading to TMPRSS2:ERG fusion are frequent in prostate cancer. They predominantly occur in young patients and have been suggested as a molecular classifier distinguishing fusion type from non-fusion type prostate cancer. Several studies had recently proposed intratumoral heterogeneity of these fusions. Aim of this study was to determine frequency and extent of ERG fusion heterogeneity in early-onset prostate cancer (patients younger than 50) and in elderly patients. Methods The prostates from 55 EO-PCA and 62 elderly prostate cancer patients were reviewed for presence of cancer foci. All 1,465 tumor containing sections patients were analyzed by immunohistochemistry for ERG expression. Results The prostates of these patients contained one tumor focus in 41, 2 tumor foci in 19, 3 tumor foci in 27, 4 tumor foci in 16, and 5 or more tumor foci in 12 patients. In small cancer foci (≤3mm), ERG staining was always homogeneous (30% ERG positive, 70% negative). The fraction of homogeneously positive cancers did not vary significantly with tumor focus size but the fraction of heterogeneous cases continuously increased with tumor focus size to 38% in cancers measuring ≥22mm. Due to the frequent multifocality of prostate cancer, only few cancers were homogeneously ERG positive on a patient level. ERG expression was markedly more frequent in EO-PCA than in elderly patients. In EO-PCA, 11% of cancers were homogeneously and 67% were heterogeneously ERG positive. In elderly patients 2% of cancers were homogeneously and 58% were heterogeneously ERG positive (p=0.0195). Conclusions In summary, these data show, that about 20-25% of prostate cancer foci have ERG fusions occurring early – potentially at the stage of cancer initiation. Subpopulations with ERG fusions subsequently occur in about 50% of initially ERG negative cancer foci. Mostly due to the multifocality of prostate cancer, the vast majority of cancers are heterogeneous for TMPRSS2:ERG fusions on a patient level. This challenges the concept of classifying prostate cancer patients into “fusion type” from “non-fusion type” prostate cancer. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e506-e507 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Meike Adam More articles by this author Christina Maria Tsourlakis More articles by this author Annegret Stender More articles by this author Ronald Simon More articles by this author Hans Heinzer More articles by this author Guido Sauter More articles by this author Sarah Minner More articles by this author Thorsten Schlomm More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...