Abstract A006: A randomized controlled trial of a mobile symptom monitoring app and tailored messages: Differences in outcomes among Black and White women with breast cancer on adjuvant endocrine therapy

Black women with early-stage, hormone receptor-positive breast cancer have lower adjuvant endocrine therapy (AET) adherence and higher symptom burden than White women. We compared the effects of a symptom monitoring app and tailored messages on treatment-relevant outcomes among Black and White women with breast cancer starting AET. Patients prescribed AET for early-stage breast cancer at a cancer center from November 2018 until June 2021 were randomized into: (1) an “App” group that received instructions and access to the study app and weekly text reminders to use it (n=94); (2) an “App+Feedback (AF)” group that received additional weekly tailored messages about managing symptoms, adherence, and communication (n=100); or (3) a “Usual Care (UC)” group without app access (n=102). The intervention lasted 6-months, and participants completed surveys at enrollment and 12-months. Increasing/severe symptoms and missed doses triggered alerts that prompted follow-ups from the oncology team. Outcomes included AET adherence, captured with an electronically monitored pillbox, app use, alerts, symptom burden (FACT-ES), quality of life (SF-12), self-efficacy for managing symptoms (PROMIS 1.0), and healthcare utilization (6-month count of emergency department visits/urgent care/hospitalizations, and office visits). Analyses stratified by self-reported race. Overall, 102 (34%) Black and 194 (66%) White women were randomized. Retention at 12-months was 88%. Median age was higher among White participants (60 vs. 55 years, p