Newly published study results revealed that use of the Breast Cancer Index (BCI) test led to physicians changing their long-term antiestrogen treatment recommendations for 40% of patients with early-stage hormone receptor–positive breast cancer. The results, which suggest that many women may be over- or undertreated without the incorporation of BCI, reflect real-world data from the largest prospective study assessing the impact of the BCI test on treatment decisions. The study was published by Tara Sanft, MD, and colleagues in JNCCN–Journal of the National Comprehensive Cancer Network.
Tara Sanft, MD
About the BCI
Previous studies have demonstrated that while some women with early-stage hormone receptor–positive breast cancer may reduce their risk of cancer recurrence with a longer course of antiestrogen therapy (10 vs 5 years), most women do not benefit. The BCI test is a molecular, gene-expression–based test uniquely positioned to provide information to help physicians individualize treatment decisions for patients with early-stage hormone receptor–positive breast cancer. The BCI test has guideline designation from the American Joint Committee on Cancer (AJCC) for cancer staging based on molecular profile. ASCO, the European Group on Tumor Markers (EGTM), and the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) acknowledge the BCI test as a biomarker to inform the extended endocrine treatment decision; and ASCO, EGTM, and St. Gallen acknowledge the BCI test as a biomarker to inform the chemotherapy decision.
Key Study Results
The key results from the study underscore the value of BCI in helping to avoid:
- Overtreatment: Of the physician treatment decisions that changed, 63% changed from a yes to a no recommendation for extended antiestrogen therapy duration. This finding suggests a critical role of BCI in helping identify women whose treatment may be discontinued after the first 5 years to avoid potential side effects and toxicities associated with a longer duration of antiestrogen therapy.
- Undertreatment: The remaining 37% of changes in treatment decisions by physicians were from a no to a yes recommendation for extended antiestrogen therapy. This result highlights an equally important use of BCI: to identify women who may benefit from longer treatment to help avoid a potentially life-threatening metastatic recurrence when extended therapy may not have been previously recommended based on clinical and pathologic risk features alone.
“These results further reinforce the impact of the BCI test in clinical practice. For many physicians, the test results changed their recommendations for prescribing or not prescribing extended antiestrogen therapy for patients based on the predictive benefit,” said Dr. Sanft, the study’s primary author, Associate Professor of Medicine at Yale School of Medicine and Chief Patient Experience Officer at Smilow Cancer Hospital. “As clinicians, we always strive to give our patients the best clinical advice possible. The BCI helps us prevent over- and undertreatment for extended antiestrogen therapy and is an incredibly helpful tool, giving us more confidence in our treatment decisions for breast cancer patients.”
Patients and physicians included in this study are participants in the BCI Registry Study, a prospective, large-scale, multicenter study that investigates long-term clinical outcomes, decision impact, and medication adherence in patients with early-stage hormone receptor–positive breast cancer receiving BCI testing as part of routine clinical care. The study concluded with the enrollment of over 3,000 patients who will continue to be followed until 10 years from diagnosis. The current publication reports results assessing the impact of BCI on clinical decision-making regarding extended antiestrogen therapy in the first 1,000 patients enrolled in the BCI Registry Study.
In addition, the new findings revealed that when incorporated into routine clinical care, BCI has the potential to provide clinicians with greater confidence in their treatment recommendations, with 39% of providers saying they felt more confident in their recommendation for extended antiestrogen therapy following BCI testing. Additionally, BCI testing led to 41% of patients feeling more comfortable with their treatment decisions and 45% changing their preference regarding an additional 5 years of antiestrogen therapy.
Disclosure: For full disclosures of the study authors, visit jnccn.org.
