Text-based electronic patient-reported outcome monitoring in oncology: A 180-day longitudinal analysis of symptom burden changes in 701 cancer patients.

11113 Background: Digital electronic patient-reported outcome (ePRO) systems promise to improve symptom management in oncology, yet evidence demonstrating sustained clinical benefit across diverse cancer populations remains limited. This study evaluated the longitudinal effectiveness of a text-based ePRO platform delivering weekly validated symptom assessments in reducing overall symptom burden among cancer patients over 180 days. Methods: This retrospective study consisted of 701 patients with cancer recruited between 2022–2025. The patients were eligible if they were on the platform for at least 90 days, completed the baseline survey within 14 days of enrollment, and had a survey completion rate of at least 30%. ePRO responses triggered review by a virtual care team that provided protocolized symptom management outreach and triage in collaboration with treating oncology practices. The primary outcome was the change in overall symptom burden over 180 days, measured by the Edmonton Symptom Assessment System (ESAS; total score 0–90). Secondary outcomes included physical symptoms (0–60), emotional symptoms (0–20), and well-being (0–10). Stratified analyses were done using paired t-tests. Results: The final cohort (mean age 64.6 years; 57.2% female; 20.5% metastatic; mean adherence 66.1%) demonstrated significant reduction in total symptom burden (20.99 to 18.11 points; -2.89 points, -13.7%, p < 0.001) and physical symptoms (14.86 to 12.18 points; -2.68 points, -17.0%, p < 0.001). Emotional symptoms and well-being showed no significant change. Efficacy was engagement-dependent: high-engagement patients (N = 465) achieved -2.80-point reduction (p < 0.001) versus non-significant changes in medium/low-engagement groups. Stratified analyses revealed heterogeneity: breast cancer patients demonstrated exceptional response (-8.96 points, -46.3%, p = 0.008), while GI cancer patients showed resistance (-0.43 points, p = 0.915). Non-metastatic patients (-3.06 points, p < 0.001), females (-3.27 points, p < 0.001), and patients aged < 50 years (-4.28 points, p = 0.011) demonstrated superior outcomes compared to metastatic, male, and elderly (≥75 years) patients. Conclusions: Text-based digital ePRO monitoring significantly reduced symptom burden in cancer patients over 180 days, with physical symptom improvement as the primary driver. Clinical benefit was engagement-dependent and varied substantially by cancer type, metastatic status, age, and gender. These findings validate the clinical utility of SMS-delivered ePRO systems while identifying highly responsive populations (breast cancer, non-metastatic, younger patients) and vulnerable subgroups requiring enhanced symptom management support.