Newly Published Results Reveal a Significant Proportion of Early-Stage HR+ Breast Cancer Survivors May Be Over- or Undertreated Without Breast Cancer Index Genomic Testing

Hologic, Inc. (Nasdaq: HOLX) and its subsidiary, Biotheranostics, Inc., today 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-estrogen 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.

“These results further reinforce the impact of the Breast Cancer Index test in clinical practice. For many physicians, the test results changed their recommendations for prescribing or not prescribing extended anti-estrogen therapy for patients based on the predictive benefit,” said Tara Sanft, M.D., 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 Breast Cancer Index helps us prevent over- and undertreatment for extended anti-estrogen therapy and is an incredibly helpful tool, giving us more confidence in our treatment decisions for breast cancer patients.”