PS5-10-30: A randomized survey study of structured reflective questions and willingness to participate in window of opportunity trials

Background: Clinical trials are critical to advancing cancer care but often raise patient concerns regarding treatment delays, additional procedures and visits, and toxicity. Understanding factors that influence trial enrollment decisions is essential for patient-centered trial design. Window of opportunity trials, which introduce investigational therapies between diagnosis and standard treatment initiation and are increasingly important in breast cancer research, exemplify a design where these concerns may be magnified. Limited data exist on patients’ evaluation of participation in such trials. Methods: We conducted a randomized survey study to determine patients’ willingness to participate in a window of opportunity trial. Adults (≥18 years) with a self-reported history of stage 0-III breast cancer were recruited via advocacy organizations, online social media platforms, and IRB-approved outreach at breast oncology clinics. All participants were first presented with a standardized definition and visual representation of a window of opportunity trial. They were then randomized in a 2:1 ratio to receive the primary endpoint question assessing willingness to participate either after exposure to reflective questions about potential barriers (e.g., additional biopsies, clinic visits, treatment delays) and motivators (e.g., desire to contribute to science), or immediately without prior reflective questions. Participants were also asked to answer questions about demographics and clinical characteristics as well as attitudes toward clinical research using the Corbie-Smith Index. The primary endpoint was willingness to participate, assessed on a Likert scale. Results: Of 1,104 total responses, 874 met eligibility criteria and 749 completed the primary endpoint question and were included in the analytic cohort. Respondents were primarily female (99%), non-Hispanic White (76%), and college-educated (64%). Among survey respondents, those Participants exposed to reflective questions before the primary question were significantly more likely to express willingness to enroll in a window of opportunity trial (76% vs 64%, OR 1.88, 95% CI 1.22-2.90; P < 0.001). Most demographic and clinical features did not correlate with willingness to participate, including age, race and ethnicity, income, location of treatment (academic vs community), geographic location (urban vs suburban vs rural), time since breast cancer diagnosis, nodal involvement, patient assessment of risk of recurrence, and initial treatment after diagnosis (surgery vs systemic therapy); an exception was that willingness was higher among those without a college degree (80% vs. 71%; P = 0.027), not significant after multiple hypothesis testing. Research distrust (Corbie-Smith Index) was significantly associated with lower willingness to participate (P < 0.001). Willing participants were more open to additional procedures, with 93% accepting at least one biopsy (vs. 57% of those unwilling) and 48% accepting five or more extra clinic visits (vs. 23% of those unwilling). Conclusions: After exposure to reflective questions addressing potential barriers and motivators, participants had significantly greater willingness to participate in a window of opportunity trial. The effect of reflective question exposure on willingness to participate was substantially greater than that of any demographic or clinical characteristic measured in our survey, emphasizing the potential of simple, scalable behavioral strategies to improve patient engagement in clinical trials. These results have important implications for the development of both digital tools and face-to-face communication strategies to enhance clinical trial enrollment and patient satisfaction in early-stage breast cancer treatment Citation Format: C. Bergstrom, D. Parikh, S. Brain, D. Heditsian, V. Lee, B. Shaw, C. Thompson, G. Sledge Jr, J. Caswell-Jin. A randomized survey study of structured reflective questions and willingness to participate in window of opportunity trials [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 PS5-10-30.