Editor’s Note: The following article was originally written and shared with us by Adriana Olivo, NP, Memorial Sloan Kettering Cancer Center.
For many people with hormone receptor-positive (HR+), early-stage breast cancer, the longest part of treatment is not surgery, chemotherapy, or radiation. It is living for years with the physical and emotional impact of endocrine therapy while wondering what comes next.
Endocrine therapy, also referred to as anti-estrogen therapy or hormone therapy, includes treatments like aromatase inhibitors (AIs) and tamoxifen. After active treatment ends, many patients are placed on these medications to help reduce the risk of breast cancer recurrence. These treatments can be highly effective, but they can also affect quality of life in ways that are difficult to ignore. Joint pain, hot flashes, fatigue, sleep disturbances, mood changes, and sexual health concerns are common. A recently published study shows that 83% of patients receiving endocrine therapy experience side effects.1 Balancing quality of life concerns with treatment efficacy becomes incredibly important for providers and patients to develop personalized treatment plans.
Why Personalized Information Matters
Unlike some other breast cancer subtypes, hormone receptor-positive breast cancer has a risk of recurrence that can persist well beyond the first five years after diagnosis.2 Because of this ongoing risk, healthcare providers may recommend extending endocrine therapy beyond the standard five years. However, extended treatment is not beneficial for every patient, and additional years of therapy may mean additional years of side effects.
As patients approach the five-year mark of endocrine therapy, they often face a difficult decision: should treatment continue for several more years? Many worry about stopping too soon and increasing their risk of recurrence. Others question whether the benefits of continuing treatment outweigh the ongoing impact on their quality of life. In fact, 61% of patients reported that it would have been helpful to have greater clarity from the beginning about how long they would need to take anti-estrogen therapy.3
That is where the Breast Cancer Index® (BCI®) test may help.
What Is the Breast Cancer Index Test?
The Breast Cancer Index test is a genomic test that analyzes tissue from a patient’s breast tumor using a sample collected during the original surgery or biopsy. The test provides information about a patient’s risk of distant recurrence, meaning cancer returning elsewhere in the body, and whether that patient is likely to benefit from continuing endocrine therapy after the first five years.
New Study Shows the BCI Test Influences Both Treatment Decisions and Patient Comfort
A recently published decision impact study evaluated nearly 3,000 women with early-stage, HR+ breast cancer enrolled in the prospective BCI Registry. The study found that physicians changed their recommendations regarding extended endocrine therapy in approximately 42% of patients after receiving BCI test results.1
Furthermore, after receiving their BCI test results, 51% of patients changed their preferences regarding extended anti-estrogen therapy and 43% of patients felt more comfortable with their treatment decisions following BCI testing.1 These results reveal the powerful impact of the BCI test in guiding personalized decisions.
Another notable finding involved fear of cancer recurrence, a concern that many breast cancer survivors know all too well. Research shows that 78% of women experience moderate or severe fear of cancer recurrence after a breast cancer diagnosis.4 Researchers found that patients identified by BCI testing as having a low risk of late distant recurrence experienced a decrease in fear of recurrence following testing.1
Supporting More Personalized Care
The Breast Cancer Index test provides individualized information that can help patients and their healthcare providers have more informed conversations about risk, treatment benefit, quality of life, and personal preferences, so patients have a clear roadmap of what to expect from their care.
References:
- Sanft T, et al. JAMA Netw Open. 2026;9(9):e2634974.
- Lancet 2005;365:1687-71. 2. Saphner T, et al. J Clin Oncol 1996;14:2738-4.
- Data collected from 192 early-stage, HR+ breast cancer patients in an online survey conducted by Living Beyond Breast Cancer.
- Magnani C, et al. J Cancer Surviv. 2023;17: 1359–1370.
About the Author: Adriana Olivo* is a nurse practitioner with special training in breast cancer survivorship. She is a graduate of Hunter College’s Nurse Practitioner Program and is working towards her Doctorate in Nursing Practice at Villanova University. She has been working at Memorial Sloan Kettering Cancer Center as a Nurse Practitioner since 2013. Her area of expertise is in managing the long-term effects of breast cancer treatments and improving the quality of life for breast cancer survivors. Outside of her professional practice, she enjoys spending time with her family, playing soccer, reading, and going to the beach.
* Adriana Olivo is a consultant of Biotheranostics, Inc., A Hologic Company. Statements reflect the author’s own personal views and interpretations.
