Breast cancer survivors' opinion on personalizing endocrine therapy and developing informative tools.

Understanding breast cancer survivors' perspectives is critical to personalizing endocrine therapy (ET) in the adjuvant setting. A nationwide survey among breast cancer survivors was proposed in France, in collaboration with patient advocacy organizations, to assess their perspectives on personalizing ET and developing dedicated informative tools. This survey explored patients' preferences regarding ET intake schedule, formulation, presentation (color, taste, shape, size, design, and packaging), combination with agents targeting ET-related adverse events, and a mobile application to support them during ET. Of the 1103 individuals who started the survey, 939 (85.1%) were eligible for enrollment and completed the survey. The majority of the participants considered that a personalized ET should take into consideration the intake schedule (n = 974, 90.7%) and swallowable tablet formulation (n = 606, 64.5%), without a preference for ET presentation (n = 619; 65.9%). The majority of the participants expressed a willingness to participate in a potential clinical trial evaluating the combination of ET with agents targeting ET-related adverse events at the start of ET (n = 752, 80.1%) or in the case of major ET-related adverse events (n = 778, 82.8%). The primary considerations were to have an uncompromised ET efficacy and a guaranteed reduction of adverse events. Last, a dedicated mobile application was considered helpful by 665 participants (70.8%). Informative tools should focus on the recommendations for dealing with adverse events (n = 593, 63.2%), the impact on the patient's daily life (n = 515, 54.9%), benefits (n = 504, 53.7%), and adverse events (n = 494, 52.6%) of ET. This survey paves the way for multimodal strategies that can include a personalized ET (e.g., ET in combination with agents targeting ET-related adverse events) and dedicated mobile applications to ultimately improve adherence.