The review had been requested after Quebec's Association of Pathologists released a startling report in April 2009 of a limited study that had suggested a high error rate, of between 15% and 20%, in the determination of the estrogen receptor (ER) status, an important test for the determination of appropriate treatment of breast cancer patients. In recent years, there have been other disclosures of high error rates in breast cancer testing in other provinces of Canada, including Newfoundland/Labrador, Manitoba, New Brunswick, and Ontario. Quebec is the fifth province in Canada to uncover inaccuracies in breast cancer testing.
All breast cancers from patients in North America are tested for the presence of ER, as patients with breast cancers that are ER positive generally have a more favorable outcome than those that are ER negative, and such patients can also be successfully treated with drugs such as tamoxifen.
PhenoPath Laboratories was selected to retest a total of 2,856 cases that had been originally analyzed at many laboratories in Quebec between April 1, 2008 and June 1, 2009. The retesting involved a technique called immunohistochemistry (IHC), a special technique in which tumor tissue prepared from the original biopsies can be viewed under the microscope and evaluated for the presence of ER. PhenoPath Laboratories was founded in 1998 by Dr. Allen M. Gown, an internationally recognized expert in the technique of IHC, and the laboratory has become a highly respected national reference laboratory for the performance of IHC and other specialized pathology testing of breast and other tumors. The laboratory was involved in a landmark study published in December 2006 demonstrating that reagents employed for the identification of ER in breast cancer specimens at PhenoPath Laboratories were significantly more sensitive and specific than those widely used in the United States and around the world. PhenoPath’s vast experience and expertise with IHC in this context was a major factor in the selection of this laboratory by the Province of Quebec for this retesting.
In the re-analysis, results of which were just announced, a total of 87 women were found to have received a false negative result from the original pathology laboratory tests in Quebec. Of this number, 39 were required to alter their treatment and among them five women died. Minister of Health Yves Bolduc said it was impossible to determine whether the women died as a result of being improperly treated. The Quebec government has been threatened with a class action suit by a group of patients who contend they didn't receive appropriate treatment.
Despite the relatively low rate of “false negative” ER tests revealed by the PhenoPath Laboratories retesting of the original Quebec laboratory results, given the absence of standardization and comparable retesting studies in the United States, and the additional potential sources of error not addressed in this retesting, the error rate in ER testing in breast cancer in laboratories the United States remains uncertain.
About PhenoPath Laboratories:
PhenoPath Laboratories is a national anatomic pathology reference laboratory located in Seattle, Washington. PhenoPath provides consultation services and diagnostic and research applications of immunohistochemistry (IHC), flow cytometry, FISH, CISH and PCR testing to pathologists and clinical laboratories across the United States and the world.
Allen M. Gown, M.D. email@example.com PhenoPath Laboratories, 551 North 34th Street, Suite 100, Seattle, WA 98103-8675 Telephone: 206-374-9000, 888-927-4366, FAX 206-374-9009 www.phenopath.com