Studies Show bioTheranostics’ Breast Cancer IndexSM Identifies Breast Cancer Patients at Risk for Early and Late Recurrence, and Predicts Benefit from Extended Endocrine Therapy

Information could allow many women to avoid unnecessary treatment and identify those patients more likely to benefit from continued endocrine therapy

FOR IMMEDIATE RELEASE…July 10, 2013…SAN DIEGO… bioTheranostics, developer of innovative molecular diagnostics, reported results from two new studies evaluating the performance of its Breast Cancer Index (BCI) biomarker assay in estrogen-receptor positive (ER+), early stage breast cancer. Study results showed that BCI predicts which women with early stage ER+ breast cancer are at risk for early and late distant recurrence, and which are most likely to benefit from continuing treatment with endocrine therapy after completing five years of tamoxifen.

BCI is a combinatorial biomarker with a novel mechanism of action composed of Molecular Grade Index (MGI) and the two-gene expression ratio HOXB13/IL17BR (H/I).

In a study published online in the Journal of the National Cancer Institute, tumor samples from 83 patients with breast cancer recurrence were matched to 166 patients without disease recurrence from the MA.17 trial, a landmark randomized clinical study that demonstrated improved disease-free survival with extended letrozole therapy in postmenopausal patients with ER+ breast cancer who were recurrence-free following an initial five years of tamoxifen therapy. In patients receiving extended endocrine therapy, a high H/I gene expression ratio, as measured by the BCI assay, remained significantly associated with benefit from extended endocrine therapy (p=0.0061), representing a 16.5 percent reduction in the risk of recurrence with extended letrozole treatment compared with placebo. Patients with low H/I did not benefit from extended letrozole treatment. The study authors concluded that the BCI assay identifies a subgroup of breast cancer patients diseasefree after five years of tamoxifen therapy who are at risk for late recurrence, and that high H/I predicts benefit from extended endocrine therapy. The study was conducted by researchers from leading institutions, including Massachusetts General Hospital.

A second study, published online in the journal Clinical Cancer Research, examined the ability of the BCI test to predict early (0-5 years) and late (>5 years) distant recurrence in ER+, lymph node negative breast cancer patients. The study was a retrospective analysis of tumor samples from tamoxifen-treated patients from the randomized, prospective Stockholm trial (n=317) and a multiinstitutional cohort from two academic medical centers (n=358). Within the Stockholm trial cohort, BCI stratified the majority (~65 percent) of patients as low risk, with5 years. The authors concluded that the ability of the BCI test to assess risk of both early and late distant recurrence has clinical utility for decisions of chemotherapy at diagnosis and for decisions about extended endocrine therapy beyond five years.

Richard Ding, president and CEO of bioTheranostics, said there is a growing need for novel biomarkers in ER+ early stage breast cancer that guide disease management beyond the initial 5-year window. “Breast Cancer Index is the only biomarker test that has been shown in prospective trials to predict the benefit of extended endocrine therapy,” Ding said. “The results of these key studies illustrate the importance of the BCI test in identifying which patients are at risk for early and late breast cancer recurrence, and who among them will benefit from extended endocrine therapy, which is of significant clinical value. This critical information should allow many women to avoid unnecessary treatment and for the clinical focus to be on those in most need of therapy.”

To obtain copies of the studies:

  • “Prediction of Late Disease Recurrence and Extended Adjuvant Letrozole Benefit by the HOXB13/IL17BR Biomarker,” click here.
  • “Breast Cancer Index Identifies Early Stage ER+ Breast Cancer Patients at Risk for Early and Late Distant Recurrence,” click here.

About bioTheranostics

bioTheranostics is the leading solution provider for metastatic cancer management, leveraging its unique expertise in expression profiling to develop a growing array of molecular diagnostic tests for cancer patients. The company operates a CLIA-certified, CAP-accredited diagnostic laboratory to perform its proprietary tests: the CancerTYPE ID® molecular classification test; PRÉCIS® Precision Medicine, which includes biomarker profiles for non-small cell lung and colorectal cancers, and other cancers; and
Breast Cancer IndexSM
, which quantifies risk of recurrence of estrogen receptor-positive, lymph node-negative breast cancer. bioTheranostics, a bioMérieux company, is based in San Diego. For more information, visit www.biotheranostics.com.