Hologic, Inc. and its subsidiary, Biotheranostics, Inc. announced newly published study results revealing that use of the Breast Cancer Index®? (BCI) test led to physicians changing their long-term anti-estrogen treatment recommendations for 40% of patients with early-stage hormone receptor-positive (HR+) breast cancer.1 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 in the March issue of the JNCCN -- Journal of the National Comprehensive Cancer Network.

Previous studies have demonstrated that while some women with early-stage HR+ breast cancer may reduce their risk of recurrence with longer anti-estrogen therapy (10 vs. 5 years), most women do not benefit.2-7 The BCI test is the only genomic test recognized by multiple national oncology guidelines to predict which women are likely to benefit from continuing anti-estrogen therapy beyond five years, helping optimize the duration of treatment. The key results from the JNCCN-published 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 anti-estrogen therapy.

This finding suggests a critical role of BCI in helping identify women whose treatment may be discontinued after the first five years to avoid potential side effects and toxicities associated with longer anti-est hydrogen therapy. Undertreatment: The remaining 37% of changes in treatment decisions by physicians were from a NO to a YES recommendation for extended anti-estrogen 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.

Patients and physicians included in this study are participants in the BCI Registry Study. The BCI Registry Study is a prospective, large-scale, multi-center study that investigates long-term clinical outcomes, decision impact and medication adherence in patients with early-stage HR+ 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 anti-estrogen therapy in the first 1,000 patients enrolled in the BCI Registry Study. Cancer patients look to their oncology care teams as experts for guidance in recommending the most appropriate treatment plan tailored to their individual health and needs. Ultimately, the newly published findings reveal 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 anti-estrogen 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 five years of anti-estrogen therapy.