Mp74-18 Psma Expression in High-Risk Prostate Cancer: Head-to-Head Comparison of Preoperative Psma-Pet Features and Immunohistochemistry Analysis of Bioptic Cores and Whole Mount Specimen

You have accessJournal of UrologyProstate Cancer: Detection & Screening VI (MP74), Moderated Poster 741 May 2024MP74-18 PSMA EXPRESSION IN HIGH-RISK PROSTATE CANCER: HEAD-TO-HEAD COMPARISON OF PREOPERATIVE PSMA-PET FEATURES AND IMMUNOHISTOCHEMISTRY ANALYSIS OF BIOPTIC CORES AND WHOLE MOUNT SPECIMEN Massimiliano Presutti, Matteo Droghetti, Lorenzo Bianchi, Luigia Vetrone, Riccardo Mei, Francesca Giunchi, Andrea Farolfi, Paolo Castellucci, Alessio Degiovanni, Antonietta D'Errico, Riccardo Schiavina, Michelangelo Fiorentino, Stefano Fanti, and Eugenio Brunocilla Massimiliano PresuttiMassimiliano Presutti , Matteo DroghettiMatteo Droghetti , Lorenzo BianchiLorenzo Bianchi , Luigia VetroneLuigia Vetrone , Riccardo MeiRiccardo Mei , Francesca GiunchiFrancesca Giunchi , Andrea FarolfiAndrea Farolfi , Paolo CastellucciPaolo Castellucci , Alessio DegiovanniAlessio Degiovanni , Antonietta D'ErricoAntonietta D'Errico , Riccardo SchiavinaRiccardo Schiavina , Michelangelo FiorentinoMichelangelo Fiorentino , Stefano FantiStefano Fanti , and Eugenio BrunocillaEugenio Brunocilla View All Author Informationhttps://doi.org/10.1097/01.JU.0001008632.59099.b9.18AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PSMA-PET has led to a change in the management of prostate cancer (PCa) patients, showing a superiority in sensitivity and specificity to detect PCa compared to conventional imaging and other molecular imaging techniques. Among the different factors that may contribute to PSMA-PET positivity, the role of PCa immunohistochemical (IHC) features is still poorly addressed, and especially the potential utility of biopsy core staining and its correspondence with final pathological specimen. The primary outcome of this study was to assess the concordance between IHC features for PSMA expression of MRI index lesion at target biopsy cores and the primary tumor at whole-mount final pathological examination. The secondary outcome of the study was to evaluate the correlation between IHC features of PCa at biopsy cores and PSMA-PET parameters. METHODS: We included patients who underwent 68Ga PSMA-PET for high-risk PCa at our institution from January 2020 to December 2022 during the preoperative work up for radical prostatectomy (RP). PSMA-PET parameters such as SUVmax, relative tumour volume (RTV) and total lesion activity (TLA) were collected. MRI target biopsy cores and RP specimen were further analyzed with IHC tests. PSMA IHC features consist of Visual Score (the intensity of the stain for PSMA expression was visually quantified through a four-tiered system 0 to 3) and Visual Pattern (PSMA staining patterns, namely membranous and/or cytoplasmatic). Mann-Whitney's U Test was used to assess the correlation between median values of PET parameters and IHC features of both biopsy and final specimen. Cohen's kappa coefficient was used to assess the concordance between biopsies and final pathology's IHC features. An alpha value of 5% was set to be the threshold to determine statistical significance. RESULTS: Overall, 43 patients were available for our analyses with a median age of 66 years. Median iPSA was 9.4 ng/mL. 2 (4.7%) patients had a negative PSMA-PET for primary tumor. Median SUVmax was 15 (8.5-21.7). Median RTV and TLA were 4 (2.7-10-8) and 34.5 (14-50), respectively. 28 patients (65.1%) had a visual score 3 on biopsy. Membranous pattern was found in 74.4% of patients on biopsy cores. On final specimen, a visual score 3 was found in 76.8% of patients, and membranous pattern was found in 76.7%. Cohen's kappa coefficient between biopsy and final specimen Visual score was 0.39, while for Visual pattern was 0.38. CONCLUSIONS: The IHC features for PSMA expression of MRI target biopsy cores showed poor correlation with final pathology specimen, therefore its utility to select patients who may have PSMA expression at PSMA-PET scan is sub-optimal. However, the presence of membranous PSMA expression on biopsy specimens is related with higher disease activity on PET scan compared to cytoplasmatic expression. Source of Funding: None © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e1200 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Massimiliano Presutti More articles by this author Matteo Droghetti More articles by this author Lorenzo Bianchi More articles by this author Luigia Vetrone More articles by this author Riccardo Mei More articles by this author Francesca Giunchi More articles by this author Andrea Farolfi More articles by this author Paolo Castellucci More articles by this author Alessio Degiovanni More articles by this author Antonietta D'Errico More articles by this author Riccardo Schiavina More articles by this author Michelangelo Fiorentino More articles by this author Stefano Fanti More articles by this author Eugenio Brunocilla More articles by this author Expand All Advertisement PDF downloadLoading ...