Navigation Links
False negative results found in prognostic testing for breast cancer
Date:6/18/2014

A recent study evaluating HER2 testing in a large cohort of women with breast cancer found important limitations in the conventional way HER2 testing is performed in the US and internationally.

Dartmouth-Hitchcock Norris Cotton Cancer Center physicians and researchers retested tumor samples from a large group of women and found that 22 out of 530 women had their tumor type incorrectly classified. They reported their findings in a publication titled "Assessing the Discordance Rate between Local and Central HER2 Testing in Women with Locally Determined HER2-Negative Breast Cancer," which was published in Cancer on June 13, 2014.

Breast cancer is categorized into several subtypes based on conventional laboratory, and newer molecular tests. This study looked at the accuracy in classifying breast cancers in one particular subtype, specifically those that are "human epidermal growth factor receptor 2" or HER2 positive. What is particularly important in accurately determining HER2 in breast cancer is that when a woman's cancer tests positive for HER2, there are specific treatments proven extremely effective in improving outcome and preventing recurrence of cancer. These HER2 directed, or targeted, therapies are critically important in treating women with HER2 positive breast cancer.

"We, and other groups, have previously shown that a certain percentage of cases found to be HER2 positive in local laboratories are in fact HER2 negative when tested in more experienced central labs. There has, however, been almost no research evaluating the accuracy of a negative HER2 result," said Peter A. Kaufman, MD. "This is the first large study to look at this. What is comforting is that we found that re-testing in experienced larger labs confirmed the original local lab results in the majority of cases."

Kaufman noted that they did find about four percent of cases that were originally determined to be HER2 negative were in fact HER2 positive on repeat testing. Many of these cases were detected as being positive by testing for HER2 using both of two different and complementary tests (IHC and FISH, as described below).

The repercussions of incorrectly identifying a cancer's subtype are considerable. "While it is comforting that only four percent of these women were misclassified initially, this is an enormous issue for those who fall into this group," said Kaufman. "This is because HER2 targeted therapies are critically important for women with HER2 positive breast cancer."

The variance in accuracy may be related to how tests are conducted in smaller versus larger pathology laboratories. Two different tests are approved for and widely used for HER2: immunohistochemistry (IHC) or florescence in situ hybridization (FISH). Either test may be used to determine a woman's HER2 status. Frequently, based on recommendations by leading oncology groups, one or the other is used. In this case, using both tests allowed researchers to uncover errors resulting from reliance on a single test. Of the 22 samples incorrectly categorized, 18 had been processed by a local laboratory using only one testing method.

The analysis was based on the VIRGO study, a large, disease-based, observational cohort study of more than 1,200 women with HER2-negative metastatic breast cancer from June 2008 through January 2011. Out of the 1,267 patients enrolled in VIRGO, 776 submitted samples for this study from which 552 were suitable for centralized testing using IHC and FISH assays.


'/>"/>

Contact: Donna Dubuc
donna.M.Dubuc@Dartmouth.edu
603-653-3615
The Geisel School of Medicine at Dartmouth
Source:Eurekalert

Related medicine news :

1. False-positive mammogram anxiety has limited impact on womens well-being
2. False-positive mammograms associated with anxiety, willingness for future screening
3. New sugar-test to reduce false-positive cancer diagnoses
4. Parker Waichman LLP Reminds Whistleblowers of Their Rights under the False Claims Act as It Moves Forward with FedEx Lawsuit for Alleged Overcharging
5. Boston Scientific, Subsidiaries to Pay $30M to Settle Lawsuit Filed Under False Claims Act; Parker Waichman LLP Applauds Efforts of Whistleblower Who Gets $2.25M
6. The Federal Trade Commission Files Lawsuit Seeking an Injunction Against Marketer of Weight-loss Products Over Alleged False Advertising, Parker Waichman LLP Reports
7. Final Victory for His Holiness Nithyananda: U.S. Court Ordered Dismissal Of False Case
8. Zithromax Arrhythmia and Sudden Death Cases Allegations Update: Resource4thePeople Reports FDA Issued Warning Letter to Manufacturer over False and Misleading Information
9. Southern District of New York Settles False Claims Act Case Against Multi-State Provider Group Servicing Medicare and Medicaid Patients
10. Autoclave Manufacturers Make False Claims About FDA Approvals
11. Mammogram tool improves some breast cancer detection but also increases false alarms
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/25/2017)... Vegas, NV (PRWEB) , ... April 25, 2017 ... ... can now choose a modern procedure that achieves results in a fraction of ... in Las Vegas, NV, with Significance Dental Specialists, now offers this revolutionary ...
(Date:4/25/2017)... ... , ... Back Pain Centers of America (BPC), which connects people ... their area, announces the launch of a new and proprietary customer relationship management (CRM) ... reputable physicians to help them with back or neck pain and helps to match ...
(Date:4/25/2017)... ... April 25, 2017 , ... ... predictive analytics to its patient care management module. Using this new feature, sleep ... patient has been initiated on continuous positive airway pressure (CPAP), oral, or other ...
(Date:4/25/2017)... ... April 25, 2017 , ... Vetoquinol USA® , a ... UCII, part of the EQUISTRO line, at this week’s Rolex Kentucky Three-Day Event ... the immunologic level. , The scientifically-developed Flexadin UCII supports the body’s normal repair ...
(Date:4/24/2017)... ... April 24, 2017 , ... LG CNS Healthcare ... Device (BYOD) capabilities at Telehealth 2.0, the American Telemedicine Association’s national conference. , ... medical devices with a pre-programmed tablet in a remarkably easy-to-use kit for patients. ...
Breaking Medicine News(10 mins):
(Date:4/19/2017)... , April 19, 2017  Vanderbilt University Medical Center ... in Nashville , Tennesse have been ... Sphincter Stimulation for GERD (LESS GERD) trial. The EndoStim ... long-term reflux control by restoring normal function to the ... million people in the United States ...
(Date:4/19/2017)... N.J. , April 19, 2017  Novartis ... by the National Heart, Lung, and Blood Institute ... demonstrating that 58% of patients with treatment-naïve severe ... months when treated with eltrombopag at the initiation ... . The study evaluated three sequential treatment groups, ...
(Date:4/18/2017)... April 18, 2017 Research and Markets has ... report to their offering. ... The global arthroscopy devices market to grow at a CAGR of ... Arthroscopy Devices Market 2017-2021, has been prepared based on an in-depth ... market landscape and its growth prospects over the coming years. The ...
Breaking Medicine Technology: