Abstract PS5-11-24: Does Early Awareness of Clinical Trials Translate to Increased Adoption of Results? Factors Associated with Intent to Omit Axillary Surgery Based on the SOUND Trial

Abstract Background: Oncology trials typically take a decade to mature. We hypothesized that anticipating results may facilitate early implementation. The SOUND trial, published November 2023, demonstrated that sentinel lymph node biopsy (SNB) omission is oncologically safe for select early-stage breast cancer (EBC) patients. Here we evaluate if timing of awareness of the SOUND trial translates to increased intent to implement the SOUND trial results. Methods: This multicenter, cross-sectional study surveyed a purposive sample of North American physicians from August to December 2024 (US) and March to May 2025 (Canada) on current SNB use, when they became aware of the SOUND trial and intent to implement the trial results. Two sets of questions assessed intent on a 5-point scale: 1) Validated measure by Moulin (Innovation-Specific Implementation Intentions); 2) case questions on likelihood of omitting SNB for a 1.5cm grade 2, luminal A EBC with different patient ages and radiation plans (whole vs partial breast irradiation; WBI, PBI). The outcome of interest was intent to omit SNB to a “high extent”, defined as survey answers of ‘moderate’ to ‘very great extent’. Multiple logistic regression was performed to identify factors significantly associated with intent. Results: The overall response rate was 21% (208/1004), including 145 (72%) surgeons, 32 (16%) medical and 27 (13%) radiation oncologists. Most respondents (73.6%) were from the US; 26.4% were from Canada. The mean year respondents became aware of the SOUND trial was 2020 (range 2011-2024). At the time of the survey, 47.8% (n=99) of respondents had already omitted SNB in select patients < 70 years with EBC and 63.6% had high intent to use SOUND trial results. Among those who hadn’t omitted SNB (n=108), 59.3% had high intent to do so. Each additional year of awareness of the SOUND trial was associated with a 13% increase in the intent to omit SNB in patients < 70 years (OR 1.13, p = 0.01). Compared to physicians practicing in Western US, those in the Northeast US had a significantly higher intent to omit SNB (OR 3.87, p=0.02) but Midwest, South, and Canada did not. In the case-based question of a 60-year-old patient undergoing lumpectomy and WBI, 50.5% highly recommended omitting SNB but this decreased when the scenario changed to PBI or age 50 (Table 1); intent to omit SNB was not impacted by length of awareness of SOUND trial, years in practice, type of practice, proportion of clinical practice in breast or specialty. However, regional differences were noted with those in the Southern region and Canada being less likely to omit SNB compared to the West (OR 0.3, p=0.04; OR 0.27, p=0.03; respectively). Conclusions: Early awareness of the SOUND trial and regional differences were associated with higher intent to omit SNB. Further research is needed on dissemination strategies of trial concepts while studies are underway. Citation Format: K. Park, M. Delisle, K. Eum, M. J. Hassett, C. A. Minami, R. S. Punglia, M. Brindle, E. A. Mittendorf, T. A. King. Does Early Awareness of Clinical Trials Translate to Increased Adoption of Results? Factors Associated with Intent to Omit Axillary Surgery Based on the SOUND Trial [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 PS5-11-24.