An August 17th article from the New York Times detailed the risk of having a genetic mutation linked to breast cancer–not BRCA1 or BRCA2, but PALB2. The BRCA1 and 2 mutations are still major players when it comes to breast cancer risk, but a mutated PALB2 gene can increase someone’s risk of breast cancer anywhere from 5-9 times, depending on age. For example, for a woman of average risk, the risk of developing breast cancer before the age of 50 is about 1.5%. With a PALB2 mutation, it’s about 14%. The PALB2 connection to breast cancer was discovered in 2014 and has been frequently researched since then, but there is concern that some who had BRCA mutation testing early on have not yet been tested for this mutation. Though there is now a push to monitor people with this mutation similarly to how those with BRCA are monitored, genetic testing for PALB2 still requires a copay even with significant family history while BRCA testing has no copay.
While it may seem more convenient to do at-home genetic testing, the article below and the New York Times article both illustrate the importance and need for genetic counselors. Genetic counselors not only assess your family health history and ethnic background for different possible mutations to test for, but they also identify the best lab with the lowest costs for your specific testing needs. If you have received genetic testing for BRCA1 and 2, check that you have also been tested for PALB2 mutations. If you haven’t received genetic testing and you have a family history of breast and other cancers, reach out to a genetic counselor through your primary care provider.
The article below was originally published spring 2018 VBCF Newsletter:
The at-home DNA testing company, 23andMe, recently had their BRCA home test approved by the FDA. While some experts believe this is a great step towards transparency and helping patients understand their disease risk, many others are concerned that this testing will lead to greater misinformation.
The benefit of this at-home test is that it increases access to genetic testing. This testing is now fully covered by most insurances, but the person being tested must be determined “high risk.” As we know, not everyone has access to health insurance and some people with insurance may not fall under the guidelines of “high risk,” but still want to know their genetic risk. This kit helps make that knowledge possible. John Quillin, Ph.D., a genetic counselor from VCU Massey Cancer Center, sees some benefit: “Because of limited family structures and inheritance through men in the family, many women with hereditary breast cancer might not know they are at risk. Broad-based, accessible, affordable, direct-to-consumer testing may help increase access and awareness.”
A major concern with the test: Consumers are tested on “the three mutations in the BRCA1 and BRCA2 genes that are the most common in the Ashkenazi Jewish population. Those mutations are not the most common BRCA mutations in the broader population.” For context, there are “more than 1,000 known BRCA1 and BRCA2 mutations”. This means that your average consumer will take the test at home, it will come back negative for those three mutations, and they will believe themselves “safe” from breast cancer.
Genetic testing is a complicated process, which is why there are genetic counselors dedicated to helping people decide whether or not to get tested, and what to get tested for. Here’s one genetic counselor’s take on the decision:
“‘[T]he problem comes in when a patient may not have an understanding of their results and potential implications for their health,’ [Karen] Grinzaid said. ‘It puts them in a position of interpreting results and finding their own resources and puts their…primary care physician, in a position of explaining results they may not understand.’”
Different mutations within the BRCA genes are more common in people with different ethnic backgrounds, and there are other genes to look at besides BRCA (including CHEK2, PALB2, etc). Genetic counselors know this information, so they can point a person in the correct direction as to which tests to get. Genetic counselors can also help patients figure out the next steps when they are clearly at high risk due to their family history, but get negative results or results of mutation of unknown significance. Dr. Quillin highlighted another concern: “… while the FDA affirmed the validity of [23andMe’s] test results, 23andMe does not run additional confirmatory testing of positive test results, which typically happens in a clinical diagnostic laboratory.”
Genetic risk is not the only factor in developing breast cancer, in fact, only about 10% of breast cancer diagnoses are known to be affected by genetic risk. No matter your results on a genetic test, you can reduce your risk of breast cancer by exercising, eating a healthy diet, and not smoking. If you are interested in learning more about your genetic risk for breast cancer, talk to your doctor about connecting with a genetic counselor.
Sources:
Byrd, Leha. “VCU News.” Direct-to-consumer Cancer Testing Could Be Beneficial, Massey Expert Says, but It’s Not a Substitute. March 27, 2018. Accessed April 02, 2018.
“Risk Management Guidelines.” NCCN Guidelines for Genetic Counseling. December 24, 2017. Accessed April 02, 2018.
http://www.facingourrisk.org/understanding-brca-and-hboc/information/risk-management/introduction/basics/guidelines_for_genetic_counseling.php#text.
Johnson, Carolyn Y. “23andMe Gets FDA Approval to Report Breast Cancer Risk without a Doctor.” The Washington Post. March 06, 2018. Accessed April 02, 2018.
https://www.washingtonpost.com/news/wonk/wp/2018/03/06/23andme-gets-fda-approval-to-report-breast-cancer-risk-without-a-doctor/?utm_term=.db6cac2a87b5.
Jones, Kira. “FDA-Approved Breast Cancer DNA Test by 23andMe May Do More Harm than Good.” Breast Cancer Action. March 07, 2018. Accessed April 02, 2018. https://bcaction.org/2018/03/07/fda-approved-breast-cancer-dna-test-by-23andme-may-do-more-harm-than-good/.
Cunningham, Paige Winfield. “Analysis | The Health 202: Why the Medical Community Is Concerned about a Genetic Testing Boom.” The Washington Post. March 27, 2018. Accessed April 02, 2018.
https://www.washingtonpost.com/news/powerpost/paloma/the-health-202/2018/03/27/the-health-202-why-the-medical-community-is-concerned-about-a-genetic-testing-boom/5ab90d8530fb042a378a2e7f/?utm_term=.b6ea2afa85f7.
Byrd, ”Direct-to-consumer cancer testing”
“Genetics: Breast Cancer Risk Factors.” Breastcancer.org. Accessed April 02, 2018. http://www.breastcancer.org/risk/factors/genetics.
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