Breast Cancer Index Reclassified 42% of Patients into Different Risk Groups with Substantial Differences in Patient Outcomes

FOR IMMEDIATE RELEASE…June 2, 2016…SAN DIEGO…Clinical Cancer Research, the official journal of the American Association for Cancer Research, reported results of an analysis within the Arimidex, Tamoxifen, Alone or Combination (TransATAC) randomized controlled trial. In this head‑to‑head comparison of the prognostic strength of Breast Cancer Index (BCI) and Oncotype DX in early‑stage, estrogen receptor‑positive (ER+), lymph node‑negative breast cancer patients, BCI out‑performed Oncotype DX when assessing risk of cancer recurrence out to 10 years and re‑categorized the majority of patients with clinically challenging Oncotype DX Intermediate Recurrence Scores (RS). This data underscores the prognostic accuracy of BCI in early‑stage, ER+, lymph node‑negative patients, for planning personalized breast cancer treatment at both diagnosis and beyond year five. The manuscript (160155) can be viewed here.

In 42% of cases, BCI reclassified patients into different risk categories than RS with statistically significant differences in patient outcomes. Out of 178 women classified by Oncotype DX RS as intermediate risk of distant recurrence, BCI reclassified 53% of these patients to low risk with a 10‑year risk of distant recurrence of 7.1%, and 19% into high risk with a 10‑year risk of distant recurrence of 27.8%. BCI also reclassified 22% of patients grouped as RS low risk to BCI intermediate risk, and 5% to BCI high risk of distant cancer recurrence. These data indicate BCI identifies subsets of RS Low and RS Intermediate risk patients as actually having significant and clinically relevant rates of distant recurrence.

Conversely, Oncotype DX did not reclassify patients in the different BCI risk groups with statistical significance. This analysis demonstrates BCI may provide clarification to RS Intermediate results and identify RS Low patients who may be at higher risk for late distant recurrence. The study compared the validated commercially‑available assays.

"Breast Cancer Index, a second generation tool designed to answer questions about recurrence and inform treatment decisions, now has demonstrated meaningful and significant prognostic accuracy vs. Oncotype RS for early‑stage, ER+, lymph node-negative patients," said Nicolas Barthelemy, president and CEO of Biotheranostics. "Our test will help enhance personalized breast cancer treatment, by identifying accurate risk of recurrence throughout the patient journey."

Study Design

In the independent TransATAC study, existing tumor samples of 665 postmenopausal women with lymph node‑negative, hormone receptor‑positive breast cancer treated with either tamoxifen or anastrozole alone were evaluated. Analysis began at diagnosis through year 10. BCI Risk Score and Oncotype DX RS were compared to determine prognostic strength.

About Breast Cancer IndexSM

BCI is a molecular, gene expression‑based test uniquely positioned to help identify patients best suited for extended endocrine treatment. It is the only validated, commercially available test with data demonstrating prognostic risk of recurrence out to 15 years, as well as prediction of likelihood of benefit from extended endocrine therapy (treatment in years 5‑10). The breakthrough test helps oncologists and patients navigate the difficult trade‑off between wanting to take steps to prevent recurrence of their disease and facing significant side effects and safety challenges related to extended endocrine therapy. For more information, visit www.breastcancerindex.com.

About Biotheranostics

Biotheranostics, Inc., is a leader in helping physicians improve the care of cancer patients, offering a suite of proprietary molecular diagnostic tests that allow treatment to be tailored to individual patients. The company's CancerTYPE ID® is the most rigorously validated gene expression test for metastatic patients with diagnostic ambiguity, helping physicians determine optimal site‑directed treatment regimens with the goal of improving patient outcomes. Its Breast Cancer IndexSM helps oncologists make difficult decisions about extended endocrine therapy for ER+ breast cancer patients based on its unique ability to predict risk of late disease recurrence and identify which patients are likely to benefit from continuing therapy beyond five years. Biotheranostics is based in San Diego. For more information, visit www.biotheranostics.com.

Breast Cancer Index Intended Use and Limitations

BCI provides a quantitative assessment of the likelihood of distant recurrence in patients diagnosed with ER+ node-negative breast cancer, and prediction of likelihood of benefit from extended (>5 year) endocrine therapy in patients who are recurrence-free after an initial 5 years of adjuvant endocrine therapy. Treatment decisions require correlation with all other clinical findings. This test was developed and its performance characteristics determined by Biotheranostics, Inc. lt has not been cleared or approved by the U.S. Food and Drug Administration. This test is used for clinical purposes. lt should not be regarded as investigational or for research. How this information is used to guide patient care is the responsibility of the physician. Biotheranostics is certified under the Clinical Laboratory lmprovement Amendments of 1988 to perform high-complexity clinical laboratory testing.

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