ESTRO 2025 - Abstract Book

S586

Clinical - Breast

ESTRO 2025

Purpose/Objective: Treatment of low-risk and in-situ breast cancers is highly variable and includes breast conserving surgery, with or without adjuvant radiotherapy, endocrine therapy, active surveillance, or mastectomy. Patient driven evidence informing treatment decisions is limited. This study explored the factors influencing patients' treatment decisions for low-risk breast cancers. Material/Methods: A qualitative study of 26 women with ductal carcinoma in situ (DCIS) or early breast cancer was conducted using semi-structured interviews over a six month period in Melbourne, Australia. Interviews were audio-recorded, transcribed and analysed thematically. Results: Four key themes were identified; understanding risk, communication around potential benefits and harms of treatment, uncertainties of overdiagnosis, and psychosocial impact of treatment. Patients' understanding of risk was a key driver in their decision to undergo more invasive management, including adjuvant radiotherapy. Convenience of treatment and fear about disease progression were held as important as potential toxicity from surgery and adjuvant radiotherapy. Conclusion: Patient preferences for managing low-risk breast cancers are diverse. Improved understanding of the benefits and harms of treatments, particularly radiotherapy, and addressing perceptions about overdiagnosis are likely to be key drivers affecting patients' attitudes toward conservative management. Objective and informed discussions addressing the potential benefits and risks of conservative surgery and adjuvant radiotherapy or active surveillance is necessary to enable shared decision making for managing low-risk breast cancer. Digital Poster Attitudes towards AI-generated risk prediction in patients with early breast cancer: an international multi center survey. Frederik Voigt Carstensen 1 , Sofie A.M. Gernaat 2 , Friederike Banning 3 , Eva Batista 4 , Desiree van den Bongard 5,6 , Merle Hattink 2 , Icro Meattini 7,8 , Jens Petersen 1 , Ivica Ratosa 9,10 , Helena M. Verkooijen 2 , Ivan Richter Vogelius 1 , Maja Vestmø Maraldo 1 , On behalf of the ARTILLERY Consortium 2 1 Department of Oncology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark. 2 Division of Imaging and Oncology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands. 3 Breast Center, Dept. of OB&GYN, LMU University Hospital, Munich, Germany. 4 Breast Unit, Champalimaud Foundation, Lisbon, Portugal. 5 Dept. of Radiation Oncology, Amsterdam UMC, Amsterdam, Netherlands. 6 Cancer Treatment and Quality of Life / Cancer Biology and Immunology, Cancer Center Amsterdam, Amsterdam, Netherlands. 7 Department of Experimental and Clinical Biomedical Sciences ‘’M. Serio’’, University of Florence, Florence, Italy. 8 Radiation Oncology & Breast Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy. 9 Division of Radiotherapy, Institute of Oncology, Zaloska cesta 2, Ljubljana, Slovenia. 10 Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana, Slovenia Purpose/Objective: Globally, breast cancer is the most common type of cancer in women (1) and patients with early breast cancer generally have a good prognosis (2). With a long life-expectancy and with 80% of patients being diagnosed after age 50 (3), there is a substantial risk of developing chronic conditions such as cardiovascular disease (CVD), osteoporosis (OP), interstitial lung disease, and weight gain (4)(5), with treatment induced toxicity being a contributing factor (6). Keywords: Preferences, radiotherapy, breast 3590