Breast Cancer Genes: Types and Testing

Sometimes, cancer can run in your family. And if you’ve inherited certain changes, or mutations, in genes called BRCA1 or BRCA2, you can have a significantly higher risk of developing breast cancer and several other cancers.

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But your genes aren’t necessarily your destiny. And knowing whether you carry one of these mutations can help you and your healthcare team make informed decisions about screening and prevention.

Cancer genetic counselor Ryan Noss, CGC, explains what BRCA genes do, who should consider genetic testing and what your results can mean for your health.

What are BRCA genes?

We all have BRCA1 and BRCA2 genes. You’ll usually hear them referred to casually as BRCA, but healthcare providers use the term “BRCA1/2.”

They’re not “bad” in themselves. It’s only if you have certain mutations, or changes, in those genes that you can be at a higher risk of cancer.

“BRCA1/2 are tumor-suppressor genes,” Noss explains. “When they’re working properly, they help prevent cells from growing and dividing out of control.”

But if you have specific mutations, the gene may not be able to do its cancer-fighting job effectively.

And while BRCA1 and BRCA2 may be the ones you hear about the most, they aren’t the only genes associated with hereditary breast cancer.

“Mutations in BRCA1 and BRCA2 are the most common ones associated with breast cancer,” he adds. “But there are actually over a dozen other genes related to breast cancer risks.”

Cancers associated with BRCA genes

BRCA stands for “BReast CAncer gene.” And a BRCA1/2 mutation can significantly affect your risk of breast cancer. It can also make you more likely to develop:

Ovarian cancer
Pancreatic cancer
Prostate cancer

Other breast cancer gene mutations can also be associated with colorectal, uterine, thyroid and other cancers.

BRCA gene testing

You can inherit BRCA1/2 mutations from either of your biological parents. So, both sides of your family history can provide important clues about your genetic risk.

But the only way to know whether you have a mutation is through genetic testing.

BRCA testing typically involves a blood test that looks for harmful changes in BRCA1 and BRCA2. Depending on your personal and family history, your healthcare team may recommend a broader panel that checks for other genes associated with hereditary cancer, too.

“If your provider thinks you could be at increased risk, they may refer you to a genetic counselor or another genetics professional,” Noss says. “They’ll review your personal and family history, discuss what testing can and can’t tell you, and help you understand your results.”

It can be scary to learn that you have a gene change linked to cancer. But keep in mind: Having a BRCA mutation doesn’t mean you have cancer. And it doesn’t mean you’re guaranteed to develop it.

“A positive BRCA1/2 mutation result means you’ve inherited the gene mutation,” Noss confirms. “Likewise, a negative result means it didn’t detect a harmful gene mutation. But it doesn’t mean you’re immune from developing cancer.”

Who should get BRCA testing?

Not everyone needs genetic testing.

“Your personal and family history are important because they provide clues that help us know whether you should be tested,” Noss reiterates.

Your team may recommend genetic testing if you:

Are diagnosed with breast cancer at a young age or have a close biological relative (grandparent, parent, aunt, uncle, child) who was
Have cancer in both breasts or more than one type of breast cancer
Have triple-negative breast cancer
Are male and developed breast cancer or have a male relative who did
Have a personal or biological family history of ovarian or pancreatic cancer
Have certain types of prostate cancer
Are of Ashkenazi Jewish ancestry and have a personal history of breast cancer
Have multiple biological relatives with breast cancer
Have a known BRCA or other cancer gene mutation in your biological family

These aren’t the only reasons your provider may recommend testing. A genetic counselor can look at your entire family tree — including relatives on both sides — to determine whether testing makes sense for you.

Of course, you may not know your family history. That’s OK. Share what do you know, and your team can help you fill in the gaps.

How to reduce your cancer risk with a BRCA mutation

Finding out that you carry a BRCA1/2 mutation can be overwhelming. You may suddenly be faced with decisions you never expected to make.

But knowing your risk gives you and your healthcare team an opportunity to act.

“If we know you have a breast cancer gene alteration, we can take extra steps to catch cancer early, when it’s most treatable,” Noss encourages. “Knowledge is power.”

Depending on the mutation and your individual risk factors, your care plan may include:

Earlier or more frequent cancer screenings to look for signs of cancer as soon as possible
Enhanced breast screening, which may involve additional kinds of imaging, like MRIs or ultrasounds
Medications that can help lower the risk of certain cancers
Risk-reducing surgery, like a preventive mastectomy, for people at particularly high risk, if they choose

Your team can also help you understand what your results may mean for your biological relatives.

The right strategy is highly individualized. Your gene change, age, family history and personal preferences all matter. And you don’t have to make any decision on your own.

Talk with a healthcare provider if you have a BRCA gene mutation or suspect that you may. They can help you understand your individual risk, talk through your concerns and come up with a plan that makes sense for you.