A case is being prepared by a group of international researchers that genetic tests that look for multiple hereditary genes suspected of being linked to breast cancer which should not be offered until they are proven to be valid and useful in practice.
One hundred inherited cancer genes including more than 20 for breast cancer are covered for such tests, made by several companies including Myriad Genertics Inc, Ambry Genetics, Invitac and Illumina Inc.
After the invalidation of patents by the U.S Supreme Court held by Myriad on BRCA1 and BRCA2, two well characterized genes that put a woman at high risk for breast, ovarian and other cancers have become increasingly popular since June 2013.
What the researchers are concerned about are lesser-known genes included in the tests.
“The reality is that we don’t have good risk estimates for mutations that occur in many of the genes on the panels,” said Fergus Couch, a breast cancer expert at Mayo Clinic in Rochester, Minnesota.
One of the 17 genetic experts who argue against the use of such panel tests in a paper published on Wednesday in the New England Journal of Medicine is Couch. In the paper, the researchers proposed that “a genomic test should not be offered until its clinical validity is established”.
Lab developed tests, at the moment, fall under the guidelines set by the Clinical Laboratory Improvement Amendments or CLIA of 1988. But such tests are not required to prove the clinical utility or validity under the CLIA, meaning that the information needs patient care.
Some experts have argued that including lesser-known genes in the tests is critical for generating enough data to determine their disease risk. But the tests can leave patients and doctors wondering what the results mean.
“It’s been pretty widely assumed that all of these genes on all of these panels have clear clinical validity,” meaning the genes are clearly associated with cancer, said University of Pennsylvania breast cancer expert Dr. Susan Domchek, a study co-author. “The point of this article was to say, we’re not finished with that step yet.”
Several insurance companies have already decided not to pay for the tests.