Most cancer occurs by chance. However, some people have a higher risk of developing cancer because of a gene error (or gene mutation) that runs in their family.
Errors in two particular genes – BRCA1 and BRCA2 – are the most talked about. BRCA1 and BRCA2 are two genes that work in a way that helps protect us from cancer. We inherit these genes from our parents.
If someone is born with one of these genes not working correctly, that person may have increased risks of certain types of cancer. These types include female breast, male breast, ovarian and prostate cancers. Other potential cancer risks include pancreatic cancer and melanoma.
In March 2018, 23andMe said it would start testing for BRCA gene mutations. The results will be part of the overall health test offered by the company. Since the announcement, I’ve received a lot of questions from patients and providers about this test. Here’s how I answer them:
What is the 23andMe BRCA test?
The 23andMe BRCA test looks for only three gene mutations. These mutations are typically found in people with Jewish ancestry. (1 in 40 carry a mutation.) But, the three mutations are uncommon in all other ancestries.
The 23andMe test is not the same test that a health care provider might order. It won’t pick up on over 1,000 other BRCA1 or BRCA2 gene mutations – all of which can also increase the risk of developing breast cancer. And, it does not look for mutations in genes beyond BRCA1 and BRCA2. Inherited mutations in other genes can increase risk for developing breast, ovarian and other cancers. So, a negative 23andMe test result doesn’t offer much reassurance.
The 23andMe test also does not look at family history and other factors. These are important when assessing someone’s risk for developing cancer. I do not recommend an at-home genetic test in place of standard genetic testing. Many at-home genetic tests raise a lot of questions and could do more harm than good. Here are a few things to think about before taking an at-home genetic test.
How do I get tested for BRCA1 and BRCA2?
It’s best to start by having a conversation with your OB-GYN or primary care provider. They can help you understand your risk for breast and ovarian cancer. From there, they can help you decide if you should meet with a genetic counselor.
A genetic counselor can help you decide if genetic testing is right for you, and can select the best test based on your family history of cancer. They’ll also discuss test results with you and help coordinate a plan for screening, if needed.
Who should get tested for BRCA gene mutations?
I usually suggest genetic testing for BRCA1, BRCA2 and other cancer-risk genes for patients who have:
- A personal or family history of cancer, including breast, colon or uterine cancer, before 50 years old;
- A personal or family history of multiple cancers (such as three or more breast cancers in the family at any age);
- A personal or family history of rare cancers, such as ovarian cancer or male breast cancer;
- A known hereditary cancer syndrome in the family, like a relative with a BRCA1 or BRCA2 mutation.
Genetic testing may help you understand your chance of developing cancer, but will not predict if cancer will occur. It is not a replacement for regular cancer screening tests, such as mammograms and colonoscopies.
What is the test for BRCA1, BRCA2 and other cancer-risk genes?
Genetic testing that I order typically involves a blood draw. (The 23andMe test uses a saliva sample.) Then, the genes are analyzed. It’s sort of like scanning an instruction manual for any spelling errors, deletions, duplications or chapters in the wrong order.
Mutations in BRCA1 and BRCA2 are the most common answer for an increased risk of breast and/or ovarian cancer. But, increased risk can also come from mutations in other genes. A genetic counselor may suggest a test that looks at multiple genes at the same time. Those tests are called hereditary cancer risk multi-gene panels. Your genetic counselor will use your personal and family history to help determine the most appropriate test for you or your family.
Does insurance cover BRCA testing?
Insurance will usually cover BRCA1 and BRCA2 and other cancer-risk gene tests if you meet certain criteria. Your genetic counselor can help answer questions about insurance coverage. They can also tell you about potential costs.
Have more questions?
I recommend checking out these resources:
- Facing Our Risk of Cancer Empowered (FORCE)
- National Society of Genetic Counselors Patient Resources
And as I mentioned before, an OB-GYN or primary care provider can also be a great starting resource. Make an appointment to meet with one at our: