Abstract PS3-11-09: Alignment between commonly measured and patient-elicited toxicities and impacts of human epidermal growth factor receptor 2-positive (HER2+) breast cancer therapies

Abstract Background. Successful development of oncology treatments relies on optimizing drug dosing by maximizing both efficacy and tolerability, thereby enhancing patients’ health-related quality of life (HRQoL). This analysis aimed to assess the extent of alignment between symptomatic toxicities and impacts measured in RCTs and those elicited as important by patients receiving neoadjuvant and adjuvant therapies for high- and low-risk stage II/III HER2+ breast cancer. Methods. A targeted literature search was conducted using the Ovid platform and the IQVIA Clinical Outcome Assessment Accelerator to identify publications reporting HRQoL data (randomized clinical trials [RCTs]) and patient-elicited experiences with breast cancer (qualitative studies). English-language publications (2013-August 2024) involving participants ≥18 years of age were included. Frequency (number of RCTs measuring the symptomatic toxicities and impacts [concepts]) was evaluated, and patient-reported prevalence values, where mentioned in at least one qualitative study, were extracted. Concepts were grouped post hoc by frequency and patient-reported prevalence. Results. Of 980 articles identified, 13 were eligible for inclusion (10 RCTs, 2 qualitative studies, and 1 systematic literature review). From these, 27 symptomatic toxicities and impacts (concepts) were extracted and grouped (Table). 5 of 13 concepts that had a prevalence of >25% in the qualitative literature were measured in ≥5 RCTs, whereas the remaining 8 were measured in <5 RCTs. Of these, 6 (distortion of taste, hot flashes, joint pain, memory loss, runny nose, and tingling sensation) were not measured by any patient-reported outcome (PRO) instrument. Inversely, 10 outcomes that were assessed in ≥5 RCTs were reported by <25% of participants. 12 concepts were redundantly measured in ≥6 RCTs by >1 PRO instrument, such as the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core Questionnaire 30 (EORTC QLQ-C30); of these concepts, 5 were identified as bothersome. Conclusions. Data regarding tolerability-related concept frequency and prevalence in patients with stage II/III HER2+ breast cancer were limited. Several of the patient-elicited concepts—particularly those with a prevalence of >25%—were not measured by any PRO instrument, whereas others were redundantly assessed by >1 PRO instrument in ≥6 RCTs; this redundancy may be due to concept inclusion in frequently used long-form legacy PRO instruments, like the EORTC QLQ-C30. Concept mapping against PRO item libraries, such as the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE), may be warranted to ensure that the most relevant symptoms and impacts are assessed in RCTs. Further qualitative research is needed to optimize item selection. Citation Format: J. Gable, M. Wraight, K. Roat, E. Kim, R. Nair, J. Buzaglo. Alignment between commonly measured and patient-elicited toxicities and impacts of human epidermal growth factor receptor 2-positive (HER2+) breast cancer therapies [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS3-11-09.