(C-154) Integrating Mixed Methods and Actigraphy to Advance Understanding of Adverse Events in Metastatic Breast Cancer: A Multi-Country Study

Background: Metastatic breast cancer (mBC) remains incurable, where treatment aims to extend survival and enhance quality of life (QoL). Despite treatment advancements, adverse events (AEs) present substantial challenges, impacting QoL, treatment adherence, and outcomes. We describe the methodology for an ongoing study aiming to provide a comprehensive understanding of patient experiences and clinical context, which is crucial to improving care.

Objectives: This study employs a novel mixed methods approach to capturing the mBC patient experience with AEs and AE management. By integrating qualitative in-depth interviews, quantitative patient-reported outcomes (PROs), retrospective chart review, and prospective actigraphy data on sleep and activity, the study seeks to explore real-world patient perspectives, treatment goals, and the impact of AEs.

Methods: Participants include females aged 18+ diagnosed with HR+/HER2- mBC or triple-negative mBC, currently receiving treatment after prior systemic therapy failures. The study consists of four integrated components:
1. Qualitative In-Depth Interviews with 12-16 US patients to capture detailed, lived experiences, including perceptions of disease and AEs,
treatment objectives, and decision-making.
2. Quantitative PROs: Cross-sectional PROs using validated instruments (e.g., EORTC QLQ-C30, FACIT-F, PROMIS) of 240 patients across the US,
France, and Germany.
3. A Retrospective Chart Review via electronic case report forms by physicians to provide clinical and demographic data on all patients.
4. Actigraphy Data from wearable devices in ~20% of patients to objectively measure activity levels and sleep patterns prospectively over 6
weeks.

Results: The integration of multiple data components provides an opportunity to build a comprehensive, multi-dimensional view of the mBC patient experience. Qualitative insights will inform quantitative analyses, while actigraphy and physician-reported data offer objective and contextual perspectives on treatment impact and clinical outcomes.

Conclusions: This study’s mixed-methods approach is designed to advance understanding of AEs and patient experiences in mBC. The findings are expected to inform strategies for improving patient-clinician communication, empowering patients and caregivers, and identifying targeted interventions to enhance QOL. Ultimately, this research aims to inform a patient-centered framework for the management of mBC, driving meaningful improvements in clinical practice and outcomes.