How Testing For BRCA In Breast Cancer Works

“I know that we often associate breast cancer, primarily the female side of the family, but the BRCA1 and BRCA2 mutations can actually be transmitted also by males,” she said.

What Are My Chances of Getting Breast Cancer if I Inherited the Harmful BRCA Variant?

According to the National Cancer Institute, about “13% of women” in the general population will develop breast cancer sometime during their lives.

By contrast, 55% to 72% of women who inherit a harmful BRCA1 or BRACA2 variant will develop breast cancer by 70 to 80 years of age.

Is Race or Ethnicity A Factor?

Yes. While the chance of carrying an inherited BRCA1 or BRCA2 mutation in the general population is about 0.2%-0.3%, if you’re of Ashkenazi Jewish descent, there’s about 2.0% likelihood of carrying the mutation in one of these two genes. These mutations are known as “founder” mutations. Norwegian, Dutch, Canadian, and Icelandic populations also have founder mutations.

If you’re not of European descent, you should still be sure to ask about BRCA testing. For example, stats on Black Americans who test positive for the variant are limited, but studies show that Black women are less likely to be tested for the mutation in the first place, even though they have a higher rate of breast cancer diagnosis at an early age, as well as a higher incidence of triple‐negative breast cancer (TNBC). BRCA testing could provide more insight into this community’s treatment options.

Should I speak with a Genetic Counselor?

If your close relatives had breast or ovarian cancer at a young age and you’re worried that you may have a harmful variant in the BRCA1 or BRCA2 gene, make an appointment to speak with your healthcare provider. Tests exist to help you learn if you’ve inherited the gene.

But before you are scheduled for these tests, it’s likely you’ll need to see a genetic counselor who will do a risk assessment. Here are a few questions the counselor will probably ask you:

• Which of your relatives had cancers?
• What kinds of cancer did they have?
• What ages were they diagnosed?

Some doctors recommend a risk assessment if you have a personal or family history of breast, ovarian, fallopian tube, or peritoneal cancer or if your ancestry is associated with having the harmful BRCA1 and BRCA2 variants.

Is There a Test I Can Take?

Your genetic counselor will discuss the benefits of testing and the appropriate genetic test you should take. If you were recently diagnosed with breast cancer, you should ask your doctor to conduct germline or genetic testing. This test will look at all sorts of inherited mutations – including BRCA.

This genetic test is most often a blood test. A doctor, nurse, or medical technician will insert a needle into your vein, usually in your arm, to draw the blood sample needed for testing. The sample is sent to a lab for DNA analysis. In some cases, you could also choose to have genetic testing via direct-to-consumer (DTC) testing. It would require you to collect a saliva sample or a mouth swab and submit the sample through the mail. You would learn about the test results on a website, by mail, or over the phone. If you go this route, genetic counseling is still recommended to help you understand the results and to be sure you took the correct test.

How Can My Results Guide Treatment?

If you test positive for the BRCA mutation, your treatments may be similar to those for BRCA-negative breast cancer, including surgery, radiation therapy, or chemotherapy, especially if this is your first diagnosis. But there are now also targeted treatments called PARP inhibitors, which have proven very effective in BRCA-positive cancers.

PARP inhibitors are a relatively new form of targeted therapy that can stop cancer cells from spreading by preventing them from repairing their damaged DNA, causing those cells to die.  PARP inhibitors like – Olaparib  (Lynparza), rucaparib (Rubraca) niraparib (Zejula), and talazoparib (Talzenna) have been approved by the FDA to treat certain cancers bearing harmful variants in BRCA1 and 2.

Olaparib, for example, has extremely impressive results. One study from a few years ago showed that olaparib (brand name: Lynparza) following surgery and/or chemotherapy significantly reduced the risk of your cancer coming back and prevented the cancer from spreading in HER2 negative, high-risk patients with the BRCA1 or BRCA2 genetic variant.

The three-year survival rate without a recurrence of what’s called invasive breast cancer was 85.9% for patients treated with olaparib, compared to 77.1% in the placebo group. New effective treatments like these for BRCA-positive cancers make it even more important to ensure you get proper genetic testing when diagnosed with breast cancer.

Metastatic Breast Cancer: Should I Get Tested For BRCA?

Breast cancer is most commonly diagnosed in the early stages when it is localized. Typically, when a patient presents with metastatic advanced breast cancer, it originated from a prior early-stage cancer that has now spread to distant sites. It is uncommon to have an initial diagnosis of metastatic breast cancer.

During your new initial diagnosis of early-stage cancer, it is likely your doctor already tested you for the BRCA mutation via genetic or germline testing, according to Dr. Tkaczuk. But there are certain circumstances where that might not have been the case:

“(Sometimes) the patient was not tested for germline mutations with genetic testing for some reason. That may have happened because they were treated many years ago or they declined that was not covered by the insurance.”

If you have not been tested for the BRCA mutation, your doctor may first check your BRCA status with molecular testing or next-generation sequencing (NGS). Next-generation sequencing looks at hundreds of mutations and alterations in your tumor – to help you and your doctor identify treatment options for you. The BRCA mutation is usually part of that tumor-based testing.

“If the next-generation sequencing is done and we have evidence that we have somatic mutations or tumor mutations in BRCA1 or BRCA2, that should actually trigger consideration for testing for germline mutations. ”

So if your next-generation sequencing results indicate there is BRCA1 or BRCA2 in your tumor – your doctor will likely consider doing germline or genetic testing to check or re-check your BRCA status. This will provide more clarity on the next steps in treatment.

Questions to Ask My Doctor

It’s understandable to feel anxious if you find out that you have the harmful variant, but recent advances in preventing, diagnosing, and treating breast cancers are promising. Speaking with your doctor about your concerns will help. Here are some questions you might want to ask:

• Have I been tested for the BRCA1 and BRCA2 mutation?
• How will my results guide treatment?
• Should I tell my children I have the harmful variant? Are there guidelines to help me do it?
• Will my insurance cover genetic testing and counseling?

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