Abstract PS3-03-18: Guidelines for Breast Cancer Index Test before and after Epic software enhancement

Abstract Background: The Breast Cancer Index® or BCI™ test is a gene-based test that analyzes two key aspects of early-stage, hormone receptor-positive breast cancer. In a first aspect, the HOXB13:IL17BR ratio (H/I) assesses how well the cancer is likely to respond to continued hormone therapy. In a second aspect, the molecular grade index (MGI) predicts the likelihood of recurrence. This combination of features helps inform the appropriate duration of endocrine therapy beyond traditional tests. Importantly, the BCI test is effective for both lymph node-negative and lymph node-positive patients. The BCI test was incorporated into the NCCN Clinical Practice Guidelines in Oncology (NCCN® Guidelines) in January 2021 and the ASCO® Clinical Practice Guideline (ASCO Guideline) in April 2022. Additionally, Epic® medical record software was recently updated to allow users to order the BCI test. We examined the frequency of BCI test orders as a quality improvement metric, both at the main campus of the City of Hope Cancer Center and our community network. Enhancing guidelines for Breast Cancer Index (BCI) testing and improvement is essential for elevating its quality and effectiveness in clinical settings. Methods: Data was obtained from Biotheranostics, Inc., for the period January 2020 to May 31,2025. We analyzed the data for testing rates with the BCI test over four time periods: pre-NCCN Guidelines (Jan 2020-Jan 2021), post-NCCN Guidelines (Jan 2021- April 2022), post- ASCO Guideline (April 2022-May 2024) and post-Epic medical record software integration (June 2024 - May 2025). Results: A total of 1456 women with early-stage breast cancer underwent testing with the BCI test during the study period. Following the NCCN Guidelines update in January 2021, there was a notable increase in adoption of testing with the BCI test, with utilization increasing by 83% (p=0.026). Following endorsement of the BCI test by the ASCO Guideline update in April 2022, there was a further increase in test ordering by 30% (p=0.22). Increased utilization of the BCI test was comparable at the main campus and our community network. The test was ordered comparably for all age groups, LN- and LN+ disease, HER2- and HER2+ patients, and pre- and post-menopausal status. The Epic software enhancement, implemented one year ago, has led to a significant year-over-year increase in test ordering: 38% on the main campus and 110% at our community site. Conclusion: The implementation of NCCN and ASCO Guidelines significantly increased BCI test utilization across all City of Hope sites. Furthermore, an Epic software enhancement dramatically improved adherence to these guidelines, leading to an even greater uptake of BCI testing. Citation Format: C. Tran, A. Deshmukh, T. Doan, N. Kethireddy, M. Elia, S. Bhardwaj, I. Kang, J. Mortimer. Guidelines for Breast Cancer Index Test before and after Epic software enhancement [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 PS3-03-18.