Background: The successful use of hormone therapy (HT) has contributed to improved 5-year cause-specific breast cancer survival rates and evidence shows that long-term use produces a larger reduction in recurrence and mortality, with nearly 50% reduction in breast cancer mortality during the second decade after diagnosis. Despite the proven benefits, hormone therapy adherence is suboptimal (less than 80% of daily doses taken) and about 33% of women who are prescribed HT do not take their medication as prescribed and are at increased risk of disease recurrence and increased mortality. Smartphone ownership has increased substantially over the past decade, providing an extraordinary opportunity for innovation in the delivery of tailored interventions to improve patients’ adherence to hormonal therapy. Purpose: We present the design and development process of a theory-based, culturally tailored, interactive mobile app to improve adherence to HT among breast cancer patients to be used in combination with patient navigation in a two-group randomized clinical trial study at the Mays Cancer Center. The intervention group (n= 60) will receive the phone app + patient navigation and the control or usual care group (n=60) will receive the information oncologists provide to patients prescribed HT. Methods: Four focus groups (n=21) were conducted with breast cancer patients and personal semi-structured interviews (n=8) with oncologists, nurses, and patient navigators from the Mays Cancer Center, to assess barriers and facilitators to hormone therapy adherence, key symptoms, app content, and features. Qualitative data informed the initial design and development of app mock-ups; these were assessed with two additional focus groups (n=10). Based on formative research, a functional phone app prototype was developed and beta-tested with five breast cancer patients, minor refinements were made, and the app is ready for recruitment. Results: Inputs from patients and healthcare team members helped to identify specific app content and features. Key themes included the importance of increasing patient education, enhancing self-efficacy, facilitating communication with the medical team and helping patients develop self-care skills to promote optimal adherence to hormone therapy. Specific app features included notification pop-ups, reminders, motivational messages, symptom tracking and management tips, educational content, social networking among patients, communication with a patient navigator, local resources and support groups, and technical support. In addition to colors, background and icon preferences, patients emphasize the need for a user-friendly app that is easy to navigate with clear educational content. Beta-testers found the app easy to use, credible and trustworthy, and their reactions were very positive about app appearance, content, purpose, and usability. Minor technical issues were fixed, and the study app was refined and finalized. Conclusions: An iterative and patient-centered design process was followed to develop a bilingual and interactive mobile app prototype to be used in a randomized control trial. The anticipated outcome is a scalable, evidence-based and easily disseminated intervention with potentially broad use to patients using HT and other oral anticancer agents.

Citation Format: Patricia Chalela, Edgar Munoz, Cliff Despres, Pramod Sukumaran, Illeana Tiemann, Victoria Paz, Bianca Gutierrez, Devasena Inupakutika, Sahak Kaghyan, David Akopian. Improving adherence to hormone therapy among breast cancer patients through a mobile app and patient navigation: App development and testing [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-38.