New Data Shows Physicians Changed Extended Endocrine Therapy Recommendations for Over 40% of Patients Following Breast Cancer Index Testing

Final analysis of 3,000-patient study shows Breast Cancer Index testing supports high rates of change in physician treatment recommendations related to extended endocrine therapy

Publication coincides with the release of an updated Breast Cancer Index test report option that allows physicians to gain earlier clinical insights at diagnosis

MARLBOROUGH, Mass.--(BUSINESS WIRE)--Hologic, Inc. and its subsidiary, Biotheranostics, Inc., today announced newly published data in JAMA Network Open showing that Breast Cancer Index® (BCI®) test results led physicians to change their extended endocrine therapy recommendations for 42% of patients. In two-thirds of those cases, physicians changed their recommendation against extending treatment.¹

The findings come from a large-scale BCI Registry Study conducted across multiple institutions at the Sarah Cannon Research Institute, involving nearly 3,000 patients with early-stage, hormone receptor-positive (HR+) breast cancer who received the BCI test. ¹

Endocrine therapy is the standard of care for breast cancer survivors to help limit the effects of hormones that can fuel cancer growth — but it is also often the longest phase of a breast cancer patient’s treatment and can cause adverse health outcomes that impact quality of life.^2-8 In this analysis, 83% of patients reported side effects ranging from muscle and joint pain to vaginal, sexual and psychological complaints.¹

“Decisions about extended endocrine therapy can be challenging, and assumptions based on standard information, such as nodal involvement and tumor size and grade, may be misleading,” said Tara B. Sanft, M.D., of Hartford Healthcare and lead author of the study. “This final analysis of the BCI Registry Study reinforces the clinical utility of the Breast Cancer Index test to provide individualized insight into tumor biology that can meaningfully change how physicians and patients approach these decisions.”

Approximately half of recurrences in HR+ breast cancer occur beyond five years post-diagnosis.⁹ Yet studies suggest that roughly 30–50% of women discontinue endocrine therapy before reaching the five-year mark, often due to side effects or uncertainty about whether continued treatment is necessary.^10-13

Multiple trials have demonstrated that while extended endocrine therapy may be beneficial for some women in reducing their risk of late recurrence, not all benefit.^14-17

As of July 2026, physicians can now access an updated report option from the same BCI test, providing additional clinical insights earlier — at the time of diagnosis — to support greater clarity as patients plan for treatment.^18-20 The updated report offers additional context on 10-year recurrence risk, which can either reinforce the case for medication adherence or help identify whether a patient’s risk may be low enough to consider a less intensive approach to endocrine therapy.

“The Breast Cancer Index test’s updated report supports a more informed plan for the years ahead, allowing physicians to further personalize patient care and provide them with a clear roadmap from the time of diagnosis,” said Lloyd Sanders, Vice President and General Manager, Oncology Services at Hologic. “That clarity can make a real difference as patients plan for treatment and life as a cancer survivor.”

The BCI test is the only genomic assay recognized by both the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) and the ASCO® Clinical Practice Guideline to predict which patients with early-stage, HR+, HER2- breast cancer are likely to benefit from extended endocrine therapy.^2-3 The test has been used by more than 10,000 healthcare providers and evaluated across multiple clinical studies involving more than 15,000 patients.^14-27

The recently published results from the BCI Registry Study solidify the clinical impact and value of the Breast Cancer Index test beyond its extensive validation and exclusive guideline recognition. Additional clinical insights from the same established test now enable earlier treatment planning and greater Clarity from the Start™.^18-20

About the Breast Cancer Index Test

The Breast Cancer Index test is a molecular, gene expression-based test uniquely positioned to provide information to help physicians individualize treatment decisions for patients with early-stage, HR+ breast cancer. This breakthrough test helps oncology care teams and patients navigate the difficult trade-offs between taking steps to prevent recurrence of their disease and facing significant side effects and safety challenges related to unnecessary treatment.

The Breast Cancer Index test has guideline designation from the American Joint Committee on Cancer for cancer staging based on molecular profile. The ASCO® Clinical Practice Guideline and the NCCN Guidelines® acknowledge the Breast Cancer Index test as a biomarker to help inform extended endocrine treatment decisions.^2-3

The Breast Cancer Index test is intended for routine clinical use, and physician treatment decisions based on results are the responsibility of the physician. It is a sole-source laboratory-developed test (LDT) performed by Biotheranostics, Inc., a CLIA-certified and CAP-accredited diagnostic laboratory. For more information and the full intended use and limitations, visit www.breastcancerindex.com.

About Hologic, Inc.

Hologic, Inc. is a global leader in women’s health dedicated to developing innovative medical technologies that effectively detect, diagnose and treat health conditions and raise the standard of care around the world. To learn more, visit www.hologic.com and connect with us on LinkedIn, Facebook, X, Instagram and YouTube.

Forward-Looking Statements

This news release may contain forward-looking information that involves risks and uncertainties, including statements about the use of Hologic products. There can be no assurance these products will achieve the benefits described herein or that such benefits will be replicated in any particular manner with respect to an individual patient, as the actual effect of the use of the products can only be determined on a case-by-case basis. In addition, there can be no assurance that these products will be commercially successful or achieve any expected level of sales. Hologic expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any such statements presented herein to reflect any change in expectations or any change in events, conditions or circumstances on which any such data or statements are based.

Hologic, Biotheranostics, Breast Cancer Index, BCI and Clarity from the Start are trademarks and/or registered trademarks of Hologic, Inc. and/or its subsidiaries in the United States and/or other countries. All other trademarks are the property of their respective owners.

References

1. Sanft T, et al. JAMA Netw Open. 2026;9(9):e2634974.
2. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Breast Cancer V.6.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed September 8, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
3. Andre F, et al. J Clin Oncol. 2022;40(16):1816-1837. Referenced with permission from the American Society of Clinical Oncology (ASCO® Clinical Practice Guideline) Clinical Practice Guideline Biomarkers for Adjuvant Endocrine and Chemotherapy in Early-Stage Breast Cancer. © American Society of Clinical Oncology. 2026. All rights reserved. To view the most recent and complete version of the guideline, go online to https://ascopubs.org/jco/special/guidelines. ASCO makes no warranties of any kind whatsoever regarding their content, use of application and disclaims any responsibility for their application or use in any way.
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