Abstract PO3-01-10: Changes in Patient-Reported Outcomes with 3 Months of Pre-operative Endocrine Therapy in the POWER Trial

Abstract Background: The Pre-Operative Window of Endocrine Therapy to Inform Radiation Therapy Decisions Trial (POWER, NCT04272801) aims to determine whether 3 months of pre-operative endocrine therapy (pre-ET) affects decision-making regarding adjuvant radiation therapy (RT) among older women with early-stage, estrogen receptor (ER) positive breast cancer. The goal of the present study is to evaluate changes in patient-reported outcomes (PROs) during the course of pre-ET. We hypothesize that PROs will change over the course of pre-ET and that those changes can be used to identify patients who are at-risk for long-term noncompliance to adjuvant ET and who may benefit from RT. Methods: Participants in the POWER Trial receive 3 months of pre-ET prior to breast-conserving surgery and final treatment decisions regarding adjuvant RT. Health-related quality of life (HRQOL) (EORTC QLQ-C30 and QLQ-BR23), depression (Center for Epidemiologic Studies Depression Scale Revised), and general symptom burden (Breast Cancer Prevention Trial Symptom Checklist (BCPT-SCL)) are assessed at baseline and at day 90 after pre-ET. Perceived sensitivity to medicine (Perceived Sensitivity to Medicine (PSM) survey) is assessed at baseline. The BCPT-SCL was used to examine common ET side effects, including hot flashes, musculoskeletal symptoms, cognitive problems, weight gain, and bladder control. Graphical methods are used to display results. Results: The first 46 participants who completed pre-ET in the POWER trial were included in this preliminary assessment. From baseline to day 90, there was notable variability in HRQOL and no definitive shift towards worsening HRQOL with a median change (IQR) of 0 (-8.33, 8.33). Similarly, the median change in symptom profiles for the whole cohort was 0 over the 90 days of pre-ET. However, a subset of patients experienced changes in symptom burden throughout the 90-day period. Approximately one-fourth of participants reported an increase in hot flashes and musculoskeletal symptoms from baseline to day 90. There does not appear to be worsening fatigue, depression scores, cognitive problems, or weight gain. After stratifying by self-perceived sensitivity to medicine, patients with high PSM scores have a greater median change (0.5 and 0.33) in symptoms compared to those with low PSM scores (0 and 0) for hot flashes and musculoskeletal symptoms, respectively (Figure 1). Conclusions: When looking at this cohort, there was no change in symptoms or quality of life after the 3-month course of pre-ET. Evaluation of the changes in PROs identified a subset of participants with worsening symptoms after pre-ET. Future analyses, when trial accrual is complete, will examine the relationship between PROs and long-term adherence to adjuvant ET and will elucidate if the patients who experience worsening BCPT-SCL symptoms during the 90-day period are more likely to opt for RT. Figure 1 Change in symptoms after pre-ET Change in hot flash burden and musculoskeletal symptom burden is greater in patients with high perceived sensitivity to medicine. Citation Format: Trish Millard, Lena Turkheimer, Christiana Brenin, David Brenin, Patrick Dillon, Einsley Janowski, Anneke Schroen, Gina Petroni, Shayna Showalter. Changes in Patient-Reported Outcomes with 3 Months of Pre-operative Endocrine Therapy in the POWER Trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-01-10.