National Study Confirms Effectiveness of New Tools for Standardizing Estrogen Receptor Testing

Results to be presented at the San Antonio Breast Cancer Symposium


BOSTON, Dec. 08, 2020 (GLOBE NEWSWIRE) -- Boston Cell Standards, announced today that it will present the results of a Canadian national study that tested the first system of reference materials for standardization of estrogen receptor (ER) testing for breast cancer. The study is being presented at the San Antonio Breast Cancer Symposium, which takes place virtually December 8 – 11.

As many previously published studies have demonstrated, high variability exists in the performance of ER testing when comparing different laboratories. For the first time, however, this new study also included immunohistochemistry (IHC) calibrators that defined a clear unit of measure—molecules of ER per cell. Using these first units of measure, traceable to a NIST standard, analytical sensitivities of individual ER assays were quantified. These new testing tools clearly demonstrated a defined analytic sensitivity threshold at which ER testing becomes suboptimal, missing most weakly positive cases. Although all the clinical ramifications of this threshold cannot be known without further studies, the new measurement tool provides critical information that can be used to track variability among laboratories, reagent lots, and even day-to-day runs, potentially lowering error rates in IHC laboratories. Termed “IHCalibrators,” these new tools were developed by Boston Cell Standards in collaboration with the National Institute of Standards and Technology (NIST). They are the first of their kind in the immunohistochemistry (IHC) industry.

The study was performed by the Canadian Immunohistochemistry Quality Control (CIQC) program. CIQC offered Canadian ER testing laboratories the opportunity to test 80 different breast cancer patient samples, as a check to verify that they obtain the correct answers. Also included were the new reference materials, capable of measuring the laboratory’s analytical sensitivity of their ER test. The performance of the new tool was correlated with the laboratory’s ability to accurately distinguish positive and negative patient samples.  

“The new tool showed a highly significant positive correlation between measured analytical sensitivity of the laboratories’ ER IHC tests with their ability to identify tumors that express low levels of estrogen receptor,” said Dr. Emina Torlakovic, Royal University Hospital, Saskatoon, SK, who directed the study. “While breast cancer patients with ER-high positive tumors would receive the correct test result and treatment irrespective of the measured analytical sensitivity, breast cancer patients with ER-low positive tumors had widely varying test results that depended on the laboratory’s test sensitivity.” Dr. Torlakovic continued. “The study did not directly examine the tests and treatments in the 80 different cases. However, the varying survey results would be expected to lead to different treatment decisions, depending on the laboratory performing the test.”

Dr. Steven Bogen, President and CEO of Boston Cell Standards, which developed the analytical tools said, “Traceability of measurement to a higher order reference is the standard of practice in all other types of clinical laboratory testing but has never before been feasible for immunohistochemistry testing. We expect its availability will lead to significant improvements in immunohistochemistry test accuracy and reproducibility. The data presented in the San Antonio Breast Cancer Symposium validate the reference materials for standardizing ER testing in the diagnosis of breast cancer.”

About Boston Cell Standards

Boston Cell Standards is the first and only company to develop and manufacture standardized reference materials in the immunohistochemistry industry. Its mission is to improve patient outcomes by ensuring that immunohistochemistry test results are accurate and reproducible regardless of where or when tests are performed. Laboratory reference materials are essential for that purpose. We bring together outstanding physicians, scientists, and staff in a creative and supportive environment with the goal of spurring groundbreaking advances that can be applied to the laboratory setting. For more information, visit


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