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Studies Identify Problems with Breast Cancer Tests
by
findingDulcinea Staff
Clinical studies raise questions about the reliability of testing methods used in determining the best course of treatment for breast cancer. Are patients receiving the wrong sort of therapy?
30-Second Summary
Breast cancer treatment has made great strides in the past few decades. Today, labs can test for specific types of proteins in cancer tissue, then use those results to help determine what treatment to offer.
For example, researchers have determined that tumors with large amounts of a protein called HER-2 are susceptible to a drug called Herceptin, while tumors with a large presence of estrogen and progesterone receptors respond well to anti-hormone treatments.
However, the test results doctors rely on to make their treatment decisions may not always be accurate, reports The Wall Street Journal. The Journal cites an analysis in the Journal of Clinical Oncology that showed that “70 percent of 105 patients [who] scored as negative on the estrogen test were relabeled as positive when the tissue was retested by an experienced lab.”
Laboratories have to demonstrate proficiency to the U.S. Centers for Medicare and Medicaid Service with regard to more than 80 types of tests, but the two breast cancer tests are not among that number.
However, the chief medical examiner for the USCMMS, Barry M. Straube, told the Journal that the breast cancer tests could be added to the regimen.
Susan G. Komen for the Cure, an organization dedicated to breast cancer research and care, last year published a white paper titled “Why Current Breast Pathology Practices Must Be Evaluated” that also raised questions about testing standards and reliability.
In the conclusion, the authors wrote: “Komen for the Cure has serious concerns about the lack of uniform standards currently available to guide the practice of breast pathology in this country." He calls for a “thorough review of breast pathology practices.”
For example, researchers have determined that tumors with large amounts of a protein called HER-2 are susceptible to a drug called Herceptin, while tumors with a large presence of estrogen and progesterone receptors respond well to anti-hormone treatments.
However, the test results doctors rely on to make their treatment decisions may not always be accurate, reports The Wall Street Journal. The Journal cites an analysis in the Journal of Clinical Oncology that showed that “70 percent of 105 patients [who] scored as negative on the estrogen test were relabeled as positive when the tissue was retested by an experienced lab.”
Laboratories have to demonstrate proficiency to the U.S. Centers for Medicare and Medicaid Service with regard to more than 80 types of tests, but the two breast cancer tests are not among that number.
However, the chief medical examiner for the USCMMS, Barry M. Straube, told the Journal that the breast cancer tests could be added to the regimen.
Susan G. Komen for the Cure, an organization dedicated to breast cancer research and care, last year published a white paper titled “Why Current Breast Pathology Practices Must Be Evaluated” that also raised questions about testing standards and reliability.
In the conclusion, the authors wrote: “Komen for the Cure has serious concerns about the lack of uniform standards currently available to guide the practice of breast pathology in this country." He calls for a “thorough review of breast pathology practices.”
Headline Links: ‘Bad Cancer Tests Drawing Scrutiny’
After receiving faulty test results in 2002, Karen Ivester tells The Wall Street Journal that she wonders whether her cancer might still be in remission if her tests had been performed correctly. Because her results were incorrect, Ivester did not receive two types of treatment, and her cancer was later rediscovered in 2006. Her new tumor and the old tumor were tested and retested, and both were positive for estrogen and progesterone receptors, which could have altered her original treatment regimen. Studies around North America have suggested the error rates when testing breast cancer tissue for different types of proteins are higher than once thought.
Source: The Wall Street Journal
Background: Testing and breast cancer types
HER-2 is both a gene and a protein, and cancer cells that have a great deal of it tend to grow more aggressively while not responding well to certain types of treatment. The test is usually part of the battery performed when someone is initially diagnosed with breast cancer.
Source: Lab Test Online
The Hormone Receptor test is another test that might be ordered when someone is first diagnosed with breast cancer. This test looks for proteins called estrogen and progesterone receptors. Those who test positive for progesterone and estrogen receptors (known as PR and ER) generally have a better prognosis, according to LabTestsOnline.org.
Source: Lab Test Online
Breast cancer isn’t just one disorder. Depending on where the cancer is discovered, how far it has spread, and the state of the cells, the cancer diagnosis can be classified in various ways. Tumors are described in three grades: grade one means the cells look similar to normal breast cells. In grade three, the tumor cells don’t have the normal structure or function properly. There is an ongoing debate as to whether breast cancers should be reclassified using other features, such as the HER-2 status, rather than the three grades.
Source: Mayo Clinic
findingDulcinea has a guide to breast cancer. Find links to breast cancer diagnosis, male breast cancer, risk factors, and ways to connect with cancer survivors in the guide.
Source: findingDulcinea
Opinion & Analysis: More pathology scrutiny advocated
A 2006 white paper from Susan G. Komen for the Cure, a breast cancer foundation, raised numerous concerns about pathology. Included in the piece were the absence of standardized, required practices; the gap between insurance reimbursement and the effort needed to analyze complicated breast samples; and training issues. The paper suggests requiring second opinions for some breast cancer patients, and making sure insurers reimburse the labs for them. A 2002 study cited in the paper showed that in 340 cases examined, second opinions agreed less than 25 percent of the time.
Source: Susan G. Komen for the Cure
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