VANCOUVER, BC - A new study in the Canadian Journal of Pathology shows a BC developed and led quality assurance program for breast cancer testing has delivered near perfect results on a national level. The program was conceived and developed by pathologists at Vancouver Coastal Health (VCH) and focuses on the HER2 breast cancer subtype.
Breast cancer is subclassified by pathologists using a process called immunohistochemistry, which determines whether a patient's breast cancer is being promoted or "fed" by hormones and if the patient’s tumour is positive for a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells.
HER2 cancers are found in about one in five women. They tend to be more aggressive than other types of breast cancer and less responsive to hormone treatment. HER2 cancers do respond very well to targeted treatment, such as Herceptin therapy, which is why an accurate diagnosis of this subtype is crucial. Traditionally, this breast cancer subtype has been very difficult to screen for with a high percentage of false positives and also disagreement of diagnosis between pathologists and laboratories.
VCH pathologists, led by Dr. Blake Gilks, division head, Anatomic Pathology at Vancouver General Hospital and professor, Department of Pathology and Laboratory Medicine, UBC, devised an innovative technique, using tissue microarray technology to validate the diagnosis. The process enables a large number of breast cancer tissue samples to be examined at one time, giving statistical power to analyse and compare results. The technology, which was the first of its kind in the world, can be used labs everywhere that might not ordinarily have the capability to monitor complex diagnosis or develop individualized quality assurance programs.
The study, published today, in the Canadian Journal of Pathology reveals the program to be effective in multiple laboratories across the country. Eighty-three samples of invasive breast cancer were tested in 39 laboratories from across Canada and the results were 99.93 % accurate, an unprecedented level of performance.
“What we saw was near perfect,” says Dr. Gilks. “Anatomic pathology is largely unregulated because testing is interpretative, dependant upon the skill, experience, and discipline of the pathologist, but with this quality assurance program, we can objectively assess the accuracy of diagnosis, which allows oncologists to confidently deliver the most effective course of treatment to patients.”
The quality control process was initially developed into a BC wide program, known as the B.C. Immunohistochemistry Testing (IHC) Quality Assurance Program, which won a 2009 BC Patient Safety and Quality Council award for advancing patient safety and quality of care. It then became a national program, Canadian Immunohistochemistry Quality Control program, in partnership with the University of Saskatchewan and the University of Toronto. Currently more than 70 labs from across Canada as well as internationally participate in this program.
NOTE TO EDITORS: The Canadian Association of Pathologists and the Canadian Society of Clinical Chemists joint conference is being held in Vancouver, June 4-8, 2011
Lisa Carver, Communications & Public Affairs
VCH/VCH Research Institute
Tel: 604. 875. 4111 (ext 61777) or (604) 319. 7533
Email: lisa.carver@vch.ca
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