The finding, presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, represents a disappointment to oncologists who had hoped to find distinct biomarkers beyond standard HER2 testing that could help them gauge how well Herceptin will work for patients.
"This study debunks the hopeful notion, strongly felt in the breast cancer community, that measuring levels of a number of different proteins in the HER2 family could help oncologists better tailor their use of Herceptin," says the study's senior investigator, Edith Perez, M.D., director of Mayo Clinic's Breast Program in Florida.
"Improving our ability to predict the benefit of Herceptin treatment beyond testing for HER2 protein and genes remains an important goal, but we are not there yet," she says.
Currently, patients are considered eligible for Herceptin if a pathologist estimates that at least 10 percent of their tumor samples test positive for HER2 growth proteins. However, the test is relatively subjective, based on a HER2 stain on a slide of tumor tissue. While the test can predict the outcome of Herceptin treatment, which shuts down the HER2 growth receptor for some patients, it cannot do so for all patients, Dr. Perez says.
Researchers used a tool that precisely measures the amount of a protein expressed in a cancer sample. According to Dr. Perez, this study was the first to meticulously measure protein levels, including HER2, HER3, HER4, EGFR (epidermal growth factor receptor), ER (estrogen receptor), and PTEN (a tumor suppressor gene) in almost 1,400 tumor biopsies.
Many researchers thought that analysis of the HER3 protein might be a good predictive marker because HER2 and HER3 interact together to promote cancer growth, Dr. Perez says.
"A biopsy could have 80 percent HER3 protein, and it wouldn't be any different in terms of a patient's outcome from Herceptin use than a tumor that had 5 percent HER3 protein," she says.
The next step to finding predictive biomarkers showing a benefit to Herceptin use will be to look at multi-gene profiles, not single biomarkers, Dr. Perez says.
The study was led by Dr. Perez and her team at Mayo Clinic with the collaboration of David Rimm, M.D., Ph.D., at Yale School of Medicine, and investigators who enrolled patients in the N9831 trial throughout the United States. The work was funded by the National Institutes of Health and the Breast Cancer Research Foundation. The original N9831 patient study was partially supported by the National Cancer Institute and Genentech.
About Mayo Clinic
Mayo Clinic is a nonprofit worldwide leader in medical care, research, and education for people from all walks of life. For more information, visit www.mayoclinic.org/about/ and www.mayoclinic.org/news.
Joe Dangor | EurekAlert!
PET imaging tracks Zika virus infection, disease progression in mouse model
20.09.2017 | US Army Medical Research Institute of Infectious Diseases
'Exciting' discovery on path to develop new type of vaccine to treat global viruses
18.09.2017 | University of Southampton
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
20.09.2017 | Life Sciences
20.09.2017 | Power and Electrical Engineering
20.09.2017 | Physics and Astronomy