- ER+ breast cancer patients reclassified as ER+ basal-type demonstrated significant response to chemotherapy underscoring critical role of advanced diagnostic tools
- Results published in Nature Publishing Group’s npj Breast Cancer
IRVINE, CALIF., U.S., and AMSTERDAM, NETHERLANDS – 24 April 2019 – Agendia, Inc., a world leader in precision oncology, today announced the publication of study results for BluePrint®, its 80-gene proprietary molecular subtyping test, in Nature Breast Cancer. It is well known that a significant subset of patients diagnosed with early stage, estrogen receptor (ER) positive (ER+) breast cancer appear to be poorly responsive to standard anti-estrogen therapy and may benefit significantly to the addition of chemotherapy. This latest study suggests that use of BluePrint® can more precisely predict tumor response to treatment and clinical outcome.
Published this week, the study, “Estrogen Receptor variants in ER-positive basal-type breast cancers responding to therapy like ER-negative breast cancers” sought to conduct a molecular analysis and clinical follow up of patients that were reclassified as ER+ Basal-type (n=91) in the Neoadjuvant Breast Registry Symphony Trial (NBRST) (n=1072). The results of the analysis showed:
- ER+ Basal-type patients revealed missing sections from the messenger RNA (mRNA) for the ER gene, ESR1, rendering the translated ER protein non-functional
- ER+ Basal-type patients experienced a far higher rate of pCR with neoadjuvant chemotherapy than did ER+ Luminal patients (34 vs. 5%)
- 3-year outcomes were comparable to triple-negative patients
Pat Whitworth, MD, Director, Nashville Breast Center and study author said, “Traditionally, the medical community has been challenged by a certain subtype of ER+ tumors that respond poorly to standard treatment. These “bad actors” read out as ER+ on standard assays even though their ER does not function well in the cell. This study shows that through diagnostic tools like BluePrint®, we now have the ability to predict and identify how a tumor might respond to treatment that goes beyond traditional molecular classifiers, to seeing the fundamental biology of an individual tumor. This diagnostic step is critical to ensuring patients get the right treatment from the start, and helps drive better long-term outcomes.”
In partnership with the Breast Cancer Research Foundation (BCRF), NBRST took breast cancers categorized by traditional pathology measures (immunohistochemistry or IHC) as ER-positive (ER+), and molecularly reclassified them with BluePrint® into one of three subtypes – Luminal, HER2 or Basal – based on gene expression patterns. Thirteen percent of these ER+ patients were reclassified as having Basal-type breast cancer and were observed to have similar clinical outcomes and response to therapy as “triple-negative” breast cancer which typically indicates chemotherapy as standard treatment. Similar to patients with triple-negative breast cancer, these ER+ Basal-type patients experienced a six-fold increase in pathologic complete response (pCR) to neoadjuvant chemotherapy compared to other ER+ patients, which resulted in significant improvement in long-term outcomes.
“What we now understand is that a diagnosis of breast cancer may encompass up to a dozen distinct diseases, all with differing prognoses and treatments. This data offers additional clarity to the oncology community’s understanding of the complexity of breast cancer, and provides further data regarding this clinically important subset of ER+ cancers. Because routine pathology cannot reliably distinguish these cancers, identifying these ER+ Basal-type cancers through subtyping with BluePrint® provides valuable new information for the optimal management of early breast cancer,” added William Audeh, MD, Medical Oncologist and Agendia Chief Medical Officer.
The study is available open access and can be found on-line at https://rdcu.be/bxGN9.
MammaPrint is an in vitro diagnostic medical device, performed as a testing service in a central laboratory, using the 70-gene expression profile of breast cancer tissue samples to assess a patient’s risk for distant metastasis. The device is FDA-cleared and CE-marked, enabling use in the European Union. MammaPrint is indicated for use by physicians as a prognostic marker only, along with other clinical-pathological factors. It is not intended to determine the outcome of disease, nor to suggest or infer an individual patient’s response to therapy. MammaPrint is the only test of its kind recommended for lymph node-negative and lymph node-positive patients by both the American Society of Clinical Oncology (ASCO) and National Comprehensive Cancer Network (NCCN®). The test is also recommended by many other national and international clinical practice guidelines.
BluePrint is an 80-gene complementary gene expression test provided with MammaPrint which allows functional molecular subtyping of a breast cancer sample into three distinct subtypes: Luminal-type, HER2-type and Basal-type, each with marked differences in long-term outcome and response to neoadjuvant chemotherapy.
In addition, Agendia has a pipeline of other genomic products in development. The company collaborates with pharmaceutical companies, leading cancer centers and academic groups to develop companion diagnostic tests in the area of oncology. For more information on Agendia or the MammaPrint and BluePrint tests, visit agendia.com. Follow Agendia, Inc. on Facebook, Twitter, or LinkedIn to keep up-to-date with the latest news.