Breast Cancer Gene Testing
There is a bit of frustrating news for women facing a battle with breast cancer.
The tests thought to be highly reliable in detecting genes which are linked to breast and ovarian cancers have been shown now to miss many cases.
“I’ve actually had breast cancer twice; I’m on my second go round so to speak.” it sounds as if Jody Rosen knower is someone with perhaps a genetic risk for breast cancer. She was first diagnosed at the age of 34! “They found an invasive tumor, it was missed by everything.”
New research says breast cancer gene testing is not as reliable as it was thought to be. The tests thought to be highly reliable in detecting genes which are linked to breast and ovarian cancers have been shown now to miss many cases.
“I’ve actually had breast cancer twice; I’m on my second go round so to speak.” It sounds as if Jody Rosen knower is someone with perhaps a genetic risk for breast cancer. She was first diagnosed at the age of 34! “They found an invasive tumor, it was missed by everything.”
Yet Jody, who was tested for the breast cancer genes brca1 and 2, turned out to be negative--.no abnormal gene was present.
But was Jody’s negative or normal test, truly normal? Or, was her test in error? It’s highly possible, according to new research in the Journal of the American Medical Association.
Study author Dr. Mary Clair King of the University of Washington, Seattle, says “There are women who carry mutations of the BRCA1 and 2 genes who receive negative which is to say normal genetic testing results who nonetheless carry cancer associated mutations which convey very high risk of breast and ovarian cancer. And those mutations cannot be detected by methods used in this country.”
The currently available breast cancer gene tests, patented by Myriad Genetics, miss several types of mutations, or alterations in the genes. Twelve percent of those with a strong family history will test negative, or normal--but still carry a dangerous abnormal copy that could lead to cancer. So the question is, when the test comes back normal, and you really suspect a genetic link, what do you then do?
Andrea Geduld, a genetic counselor at the Breast Health Resource Program at Mt. Sinai Medical Center, New York, says, “We basically advise most women to make their steps without their BRACA test. That they have to make the decision as though they are genetically positive.”
In other words, consider both very close follow up with CAT scans or MRI’s, and maybe still do preventative mastectomy--removing the breasts before cancer occurs. The long term goal: get a better breast cancer gene test!
Dr. King says, “It’s not easy. But it is technically doable. The technology needs to improved and brought to bear for these patients.”
So that for patients like Jody there’s no confusion; no second guessing.
“It’s frustrating to know it’s routinely done outside the U.S. the test for a broader specturm of genetic mutations and it’s not available here. In my case, I’d like to have the option of having that,” says Jody.
Among white women, five to ten percent of breast cancer cases are due to inherited mutations of brca1 and 2. This study found 22 different ways the genes were altered; 14 were not previously described.
Dr. King says part of the problem is the exclusive licensing of patents on genes, so that there is more than just one test in the marketplace in America.
Again, Myriad holds the patent. Dr. King says competition is the best way to improve technology and bring the price down. Myriad says it’s going to release a new test that is more accurate later in the year.