By Sara Bondell - December 17, 2018
An estimated 10 percent of breast cancers are hereditary, making genetic testing a good tool for cancer prevention, early diagnosis and creating screening and treatment plans.
But what if a woman with a genetic risk for cancer isn’t being tested?
A study published in the Journal of Clinical Oncology says the current guidelines for genetic testing for breast cancer patients limits the number of women who get tested, and therefore the tests miss almost as many patients with hereditary cancers as they find.
Out of the 1,000 women involved in the study, 83 were found to carry a cancer predisposition gene mutation. Of those, 45 women met the National Comprehensive Cancer Network’s (NCCN) criteria for testing, while 38 women did not. Researchers say those 38 women ordinarily would not have been tested if they only followed NCCN guidelines.
The NCCN guidelines for genetic testing were established 20 years ago, and recommend testing for individuals diagnosed with cancer at an early age, individuals with multiple family members affected by cancer and individuals with a rare type of cancer in their family. However, the study calls to expand the guidelines to include genetic testing of all patients with breast cancer.
“Guidelines for genetic testing is a decision that considers multifaceted factors,” said Moffitt geneticist Dr. Xia Wang. “Even a screening test which applies to everyone—with or without a history of breast cancer—may not generate a perfect result to identify all the mutation carriers because of the technology limitations. A screening test may also generate a result that causes harm, such as a false positive that causes a woman to undergo unnecessary procedures or even give up the opportunity for childbirth.”
When it comes to expanding the guidelines, Xang says widespread population screening would require an “army” of genetic professionals to interpret the test results and carry out the proper screening for those patients. “The current workforce and structure of cancer genetic professionals needs to adjust and expand significantly in order to meet the need of expansion,” she said.
Xang also says the cost of cancer genetic panel testing has dropped dramatically now that more and more individuals self-pay for testing.
Moffitt’s GeneHome Clinic not only follows the NCCN’s guidelines, but also offers other advanced screening. For example, if a woman tests normal for the high-risk common breast cancer genes, but has a significant family history of breast cancer, she can qualify to undergo advance breast screening.