ENABLE: App-based digital capture and intervention of patientreported quality of life, adverse events, and treatment satisfaction in breast cancer - study protocol for a randomized controlled trial

Abstract Background: In recent years, the treatment of breast cancer has taken the path towards personalized medicine. Based on individual tumor biology, therapy tailored to the particular subtype of cancer is increasingly being used. The aim is to find the most suitable therapy for the disease. However, the success of therapy depends to a large extent on the patient's adherence to treatment. This, in turn, depends on how the therapy is tolerated and how the treatment team cares for the patient. Patient-centered care seeks to identify and address the individual needs of each patient and to find the best form of care for that person. Objectives: In order to improve comprehensive oncological care of breast cancer patients, the ENABLE trial digitally records the health-related quality of life (HRQoL), adverse events (AEs), and patient satisfaction using a mobile smartphone application (app), responds individually to reported AEs, and offers assistance. Methods: Breast cancer patients are eligible to participate in the study before neoadjuvant, adjuvant, post-neoadjuvant, or palliative systemic therapy against breast cancer is initiated at Heidelberg, Mannheim and Tuebingen university hospitals. After 1:1 randomization into an intervention and a control arm, HRQoL assessments are performed at six fixed time points during the therapy using validated questionnaires. In the intervention group, HRQoL is also assessed briefly every week using a visual analog scale (EQ-VAS). In cases of significant deterioration, therapy-associated side effects are assessed in a graduated manner, recommendations are sent to the patient, and the treatment team is informed. Additionally, the app serves as an "eHealth companion" for education, training, and organizational support during therapy. Results: Recruitment started in March 2021; last visit is expected Q1 2024. Conclusions: Participation in the intervention arm is expected to improve treatment satisfaction, adherence, detection, and timely treatment of critical AEs. The close-meshed, weekly, brief QoL assessment will also be tested as a screening tool to detect relevant side effects during therapy. The study offers a more objective QoL assessment across treatment strategies. Trial registration: DRKS (German Clinical Trials Register)-ID: DRKS00025611 Ethical approval: S-658/2020