ESTRO 2025 - Abstract Book

S1977

Clinical - Urology

ESTRO 2025

References: 1. Shankar Siva, Mathias Bressel, Mark Sidhom, Swetha Sridharan, Ben G L Vanneste, Ryan Davey, Rebecca Montgomery, Jeremy Ruben, Farshad Foroudi, Braden Higgs, Charles Lin, Avi Raman, Nicholas Hardcastle, Michael S Hofman, Richard De Abreu Lourenco, Mark Shaw, Pascal Mancuso, Daniel Moon, Lih-Ming Wong, Nathan Lawrentschuk, Simon Wood, Nicholas R Brook, Tomas Kron, Jarad Martin, David Pryor, together with the FASTRACK II Investigator Group. Stereotactic ablative body radiotherapy for primary kidney cancer (TROG 15.03 FASTRACK II): a non-randomised phase 2 trial. Lancet Oncol 2024; 25: 308 – 16

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Digital Poster ARTO trial: BRCA status and its impact in patients with CRPC undergoing abiraterone +/- SBRT Pietro Garlatti 1 , Giulio Francolini 1 , Vanessa Di Cataldo 1 , Niccolò Bertini 1 , Michele Aquilano 2 , Saverio Caini 3 , Gianluca Ingrosso 4 , Alessio Bruni 5 , Rolando Maria D'Angelillo 6 , Luca Tagliaferri 7 , Matteo Augugliaro 8 , Luca Triggiani 9 , Silvana Parisi 10 , Gabriele Simontacchi 1 , Barbara Alicja Jereczek-Fossa 11 , Filippo Alongi 12 , Fabio Arcidiacono 13 , Andrea Lancia 14 , Marta Scorsetti 15 , Daniela Greto 1 , Mauro Loi 1 , Giulio Frosini 1 , Luca Burchini 1 , Monica Mangoni 1 , Lorenzo Livi 1 1 Radiation Oncology, Azienda Ospedaliero Universitaria Careggi, Università di Firenze, Florence, Italy. 2 CyberKnife Center, Istituto Fiorentino Di Cura E Assistenza (IFCA), Florence, Italy. 3 Cancer Risk Factors and Lifestyle Epidemiology Unit, Institute for Cancer Research, Prevention and Clinical Network (ISPRO), Florence, Italy. 4 Radiation Oncology Section, University of Perugia, Perugia, Italy. 5 Radiation Oncology Unit, University Hospital of Modena, Modena, Italy. 6 Radiotherapy Uniti, Department of Oncoematology, Policlinico Tor Vergata, Rome, Italy. 7 Radiation Oncology Department, Gemelli-ART, Università Cattolica del Sacro Cuore, Rome, Italy. 8 Radiationtherapy Unit, Azienda USL IRCCS of Reggio Emilia, Reggio Emilia, Italy. 9 Radiation Oncology Unit, ASST Spedali Civili, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy. 10 Radiation Oncology Unit, Department of Biomedical, Dental Science and Morphological and Functional Images, University of Messina, Messina, Italy. 11 Division of Radiation Oncology, European Institute of Oncology, IRCCS, Milan, Italy; Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy. 12 Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Cancer Care Center, Verona, Italy. 13 Radiotherapy Oncology Centre, "S. Maria" Hospital, Terni, Italy. 14 Department of Radiation Oncology, oliclinico San Matteo Pavia Fondazione IRCCS, Pavia, Italy. 15 Department of Biomedical Sciences, Humanitas University, Milan, Italy Purpose/Objective: ARTO trial (NCT03449719) was a multicenter, randomized phase II trial designed to assess the benefits of combining Abiraterone acetate with stereotactic body radiotherapy (SBRT) in patients with oligometastatic castrate-resistant prostate cancer (omCRPC). The trial showed that both biochemical response and biochemical progression-free survival (bPFS) were improved with the addition of SBRT compared to Abiraterone alone. This secondary analysis focuses on the prognostic impact of BRCA mutations within the trial. Material/Methods: Patients with omCRPC (defined as < 3 non-visceral metastatic lesions) were randomly assigned in a 1:1 ratio to receive either Abiraterone alone (ARM A) or Abiraterone with concomitant SBRT to all disease sites (ARM B). Here we present a post-hoc analysis focusing on BRCA status and its impact on SBRT benefit within the enrolled cohort. Results: The overall cohort included 157 patients. Of these, 89 were tested for BRCA1/2 mutations, with 80 and 9 patients testing negative and positive, respectively. Sixty-eight patients did not undergo BRCA testing. In the BRCA-negative group, bPFS events occurred in 43 patients, with 72.1% and 32.4% of patients in ARM A and ARM B, respectively, experiencing progression. In the BRCA-positive group, 6 bPFS events were recorded, with 80% and 50% of patients in ARM A and ARM B, respectively, experiencing progression. Among the BRCA-untested group, 26 bPFS events were detected, with 52.9% and 23.5% of patients in ARM A and ARM B, respectively, showing progression. No significant