Background: The Breast Cancer Index (BCI) test assay provides an individualized risk of late distant recurrence (5–10 years) and predicts the likelihood of benefitting from extended endocrine therapy (EET) in hormone receptor–positive early-stage breast cancer. This analysis aimed to assess the impact of BCI on EET decision-making in current clinical practice. Methods: The BCI Registry study evaluates long-term outcomes, decision impact, and medication adherence in patients receiving BCI testing as part of routine clinical care. Physicians and patients completed pre-BCI and post-BCI test questionnaires to assess a range of questions, including physician decision-making and confidence regarding EET; patient preferences and concerns about the cost, side effects, drug safety, and benefit of EET; and patient satisfaction regarding treatment recommendations. Pre-BCI and post-BCI test responses were compared using McNemar’s test and Wilcoxon signed rank test. Results: Pre-BCI and post-BCI questionnaires were completed for 843 physicians and 823 patients. The mean age at enrollment was 65 years, and 88.4% of patients were postmenopausal. Of the tumors, 74.7% were T1, 53.4% were grade 2, 76.0% were N0, and 13.8% were HER2-positive. Following BCI testing, physicians changed EET recommendations in 40.1% of patients (P<.0001), and 45.1% of patients changed their preferences for EET (P<.0001). In addition, 38.8% of physicians felt more confident in their recommendation (P<.0001), and 41.4% of patients felt more comfortable with their EET decision (P<.0001). Compared with baseline, significantly more patients were less concerned about the cost (20.9%; P<.0001), drug safety (25.4%; P=.0014), and benefit of EET (29.3%; P=.0002). Conclusions: This analysis in a large patient cohort of the BCI Registry confirms and extends previous findings on the significant decision-making impact of BCI on EET. Incorporating BCI into clinical practice resulted in changes in physician recommendations, increased physician confidence, improved patient satisfaction, and reduced patient concerns regarding the cost, drug safety, and benefit of EET.
Submitted July 6, 2023; final revision received September 11, 2023; accepted for publication September 12, 2023. Published online March 4, 2024.
Author contributions: Conceptualization: Sanft, Jankowitz, Pegram, Fox, O’Shaughnessy. Data analysis: Wong, O’Neal, Siuliukina, Zhang, Treuner. Methodology: Zhang, Treuner. Supervision: Sanft, Jankowitz, Pegram, Fox, Zhang, Treuner, O’Shaughnessy. Project administration: Zhang, Treuner. Visualization: Wong, O’Neal, Siuliukina. Writing—original draft: Wong, O’Neal, Siuliukina, Zhang, Treuner. Writing—review & editing: Sanft, Jankowitz, Pegram, Fox, O’Shaughnessy.
Disclosures: J. Wong has disclosed owning stock or having ownership interest in Hologic. B. O’Neal has disclosed participating in research for, being employed by, and owning stock or having ownership interest in Biotheranostics. R.C. Jankowitz has disclosed serving as a scientific advisor for Biotheranostics; and serving on a BCI steering committee for Biotheranostics. M.D. Pegram has disclosed serving as a consultant for Biotheranostics. Y. Zhang has disclosed owning stock or having ownership interest in Hologic. K. Treuner has disclosed owning stock or having ownership interest in Hologic. J.A. O’Shaughnessy has disclosed serving as a scientific advisor for Agendia, Aptitude Health, AstraZeneca, Daiichi Sankyo, Eisai, GI Therapeutics, Genentech, Eli Lilly and Company, Novartis, Ontada, Pfizer Inc., Pierre Fabre Pharmaceuticals, Roche, Samsung Bioepis, Sanofi, Seagen, and Stemline Therapeutics; and serving as a consultant for Agendia, Aptitude Health, AstraZeneca, Daiichi Sankyo, Eisai, GI Therapeutics, Genentech, Eli Lilly and Company, Novartis, Ontada, Pfizer Inc., Pierre Fabre Pharmaceuticals, Roche, Samsung Bioepis, Sanofi, Seagen, and Stemline Therapeutics. The remaining authors have disclosed that they have not received any financial consideration from any person or organization to support the preparation, analysis, results, or discussion of this article.
Supplementary material: Supplementary material associated with this article is available online at https://doi.org/10.6004/jnccn.2023.7087. The supplementary material has been supplied by the author(s) and appears in its originally submitted form. It has not been edited or vetted by JNCCN. All contents and opinions are solely those of the author. Any comments or questions related to the supplementary materials should be directed to the corresponding author.