Feasibility of Symptom Monitoring During the First Year of Endocrine Therapy for Early Breast Cancer Using Patient-Reported Outcomes Collected via Smartphone App

Treatment-associated symptoms drive early discontinuation of adjuvant endocrine therapy (ET) for breast cancer. We hypothesized that symptom monitoring with electronic patient-reported outcomes (ePROs) during adjuvant ET will enhance symptom detection, symptom management, and persistence.Eligible patients were initiating ET for stage 0-III breast cancer. Participants completed ePRO surveys via smartphone at baseline and 1, 3, 6, and 12 months. Measures included Patient-Reported Outcomes Measurement Information System Anxiety, Depression, Fatigue, and Vaginal Discomfort; plus Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events items assessing joint pain, hot flashes, vaginal dryness, concentration problems, and memory problems. Scores surpassing prespecified thresholds triggered alerts, and recommended symptom management pathways were provided to clinicians. The primary objective was to evaluate feasibility, assessed by survey completion rates, with targets of >65% for the baseline survey and ≥1 follow-up survey during the first 6 months. Secondary objectives included 12-month ET discontinuation rate (target: ≤15%), describing symptoms and evaluating pathway implementation.Among 250 participants, 73.2% completed the baseline survey and 69.6% completed ≥1 follow-up survey during the first 6 months. Thirty-one percent of participants had ≥1 symptom alert at baseline and 74% had ≥1 symptom alert during follow-up. The proportions of participants for whom pathway-concordant symptom management was documented at each time point ranged from 12.8% to 36.6%. Twenty-eight participants (11.2%) discontinued ET by 12 months.Symptom monitoring with ePROs during adjuvant ET is feasible. Despite infrequent documentation of pathway-concordant symptom management after symptom alerts, ePROs were associated with favorable short-term ET persistence.