What to Know about Genetic Testing for Breast Cancer Today

Experts say there are new reasons to get a test, including the identification of new risk-raising genes

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By:

Michelle Crouch

En español

Published October 26, 2021

For women who years ago grappled with the decision about whether or not to get genetic testing for breast cancer, experts say it may be worth going another round. Although genetic testing has long been recommended for women who have a close family history of the disease, experts are now recommending testing to others as well, including survivors of breast and ovarian cancer and women recently diagnosed with breast cancer.

In addition, they say that women who had a genetic test before 2014 should consider being tested again. That’s because today’s tests are more comprehensive, and scientists in recent years have identified additional genes linked to breast cancer.

While a genetic test can’t tell you for sure if you are going to develop cancer, it can indicate an increased risk, allowing you to take steps to reduce that risk or be more proactive about screening. If you’ve been diagnosed with cancer, knowing if you have an inherited gene mutation can help guide your treatment decisions. It can also be lifesaving for your relatives.

Even though genetic testing is easy, widely available and less expensive than it used to be, experts say many good candidates for testing haven’t been screened.

Testing for Breast Cancer?

Experts increasingly say yes.

A genetic counselor can help you assess your risk of breast cancer, discuss the risks and benefits of genetic testing, and order a test for you if you decide to move forward. Consultations are available in person, by telephone or through video call. The National Society of Genetic Counselors offers a searchable database of more than 3,300 genetic counselors.

“As a society, what we know is that we’re not maximizing the number of people getting tested who would benefit from it,” says Tuya Pal, M.D., a clinical geneticist and associate director for cancer health disparities at Vanderbilt-Ingram Cancer Center in Nashville, Tennessee. “Right now, 25 years after the discovery of BRCA1 and 2, we think maybe 20 percent of adults with BRCA1 and 2 have been identified. That means there are still a lot of unidentified high-risk people.”

Breast cancer is the second most common cancer among women in the United States (after skin cancer) and the second leading cause of cancer deaths. In 2021, about 281,550 new cases of invasive breast cancer will be diagnosed in women, according to the American Cancer Society.

Who should get tested?

Not everyone needs to be tested. The Centers for Disease Control and Prevention (CDC) recommends putting together your family health history of breast and ovarian cancer and then talking to your doctor to determine whether you’re at increased risk and if it makes sense to get tested.

Most experts agree you should be tested if:

You have been diagnosed with ovarian, pancreatic or breast cancer at a younger age (especially if it’s triple-negative breast cancer)
You are a man who has been diagnosed with breast cancer, pancreatic cancer, or high-grade or metastatic prostate cancer
You have been diagnosed with two or more types of cancer (including a second breast cancer)
You are of Ashkenazi Jewish descent. About 1 in 40 people of Ashkenazi Jewish descent in the U.S. have BRCA1 or BRCA2 mutations, compared with about 1 in 400 women in the general population
You have a family history of a known inherited mutation
You have a family history of breast cancer at a younger age, more than one family member on the same side with breast cancer, or breast cancer in a male family member
You have a close family member with a history of ovarian, pancreatic or metastatic prostate cancer

If you don’t fit into one those scenarios, you should still consider talking to a genetic counselor, because there are many other factors that can increase risk, says Joy Larsen Haidle, a genetic counselor and the cancer expert for the National Society of Genetic Counselors.

For example, people often assume you need to have multiple cases of breast cancer in your family to qualify for testing, but other cancers — including pancreatic, prostate, ovarian and colon cancer — can be caused by breast cancer gene variants. “Once you pull those together,” Larsen Haidle says, “all of a sudden things that felt disconnected to the average person are connected under one cause.”

Other candidates for testing include women who were previously treated for breast, ovarian, fallopian tube or peritoneal cancer — even if they are now cancer-free. Testing can tell them if they are at increased risk for a second cancer and also if their relatives are at risk, Larsen Haidle says.

How testing can help if you’ve already been diagnosed

If you’ve been recently diagnosed with breast cancer, your doctor may recommend genetic testing depending upon your age at diagnosis, your family history, what type of breast cancer you have and other factors.

However, some organizations, including the American Society of Breast Surgeons, say testing should be made available to all women after a breast cancer diagnosis — regardless of family history and cancer subtype — and a growing number of physicians are offering patients the choice. The genetic testing would be in addition to biopsy results that reveal which type of cancer you have or a tumor-profiling test that looks for specific mutations in tumor cells.

Genetic testing can help you and your health care provider make decisions about treatment. If you need chemotherapy, for example, your test results can help determine which specific drugs the tumor is most likely to respond to. And women with some gene mutations can benefit from a new type of medication called PARP inhibitors. “Personalized medicine — this is really what we’re moving towards,” Larsen Haidle says.

A positive test result may also influence a woman’s decision about surgery.

Take Ellen Rostker, 59, of Ann Arbor, Michigan. She was diagnosed with stage 2 breast cancer in her left breast in late 2020. Both her oncologist and her surgeon recommended genetic testing before her surgery.

After the test came back positive for an inherited mutation, Rostker decided to have a double mastectomy rather than a lumpectomy as a strategy to help prevent cancer recurrence. She also underwent six rounds of chemotherapy and is now cancer-free.

“I’m so glad I had the testing because it made my surgery decision so much easier,” Rostker says.

Why some women should get retested

Before 2014, most genetic tests for breast cancer looked only at three specific BRCA genes. It has been understood for some time that BRCA1 and BRCA2 genes are those commonly connected to hereditary breast and ovarian cancer. On average, a woman with a BRCA1 or BRCA2 gene mutation has up to a 7 in 10 chance of getting breast cancer by age 80.

What’s changed?

“We now do panel testing, which allows us to test for many more genes,” Pal says. “More and more genes are being identified that are important. And even for genes we know about, we can find more mutations now than we could in the past.”

Besides BRCA1 and BRCA2, scientists have identified about a dozen other breast cancer predisposition genes, including ATM, TP53, CHEK2, PTEN, CDH1, STK11 and PALB2. Although variations in those genes are less common, they, too, significantly increase a woman’s risk of cancer, and women who have them may want to consider more frequent screening or other steps.

Susan Berger, 69, of Glencoe, Illinois, knows firsthand how important retesting can be. She was treated for breast cancer in 1997 and underwent genetic testing in 2009. At the time, she was relieved to learn she didn’t have the BRCA gene mutations.

Earlier this year, however, she got a call from her adult daughter, who was concerned because she had recently learned she carried a PALB2 gene mutation. Many experts consider PALB2 to be the third most important breast cancer gene, after BRCA1 and BRCA2. Studies show a PALB2 mutation raises your risk of cancer by about 52 to 76 percent.

Berger took another genetic test and learned she also carries the PALB2 mutation. That information prompted her in July 2021 to have her ovaries and fallopian tubes removed to prevent cancer from developing. She also plans to have a preventive double mastectomy.

“As a 24-year breast cancer survivor and longtime health reporter, when I learned my daughter has the PALB2 mutation, I was astonished that I knew nothing about the mutation, even though it was publicly disclosed in 2014,” says Berger, who wrote about PALB2 for The New York Times and shared her experience on several national TV shows. “ ‘Knowledge is power’ has become my mantra.”

How the testing works

If you’re interested in getting genetic testing, your primary care doctor can refer you to a genetic counselor, or you can find a counselor yourself. The CDC recommends genetic counseling first to help you determine your level of risk and the best testing strategy.

Genetic testing is done with a blood test or saliva sample, and saliva or cheek swab tests can be mailed right to your home if that’s easier for you, Larsen Haidle says.

A person puts a swab into a test tube while wearing blue gloves

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Keep in mind that tests ordered by a doctor or genetic counselor are typically more complete than the direct-to-consumer tests from companies such as 23andMe, which look only for three specific BRCA variants, Larsen Haidle and Pal say.

Private insurance companies and Medicare cover the cost of genetic testing if you meet specific criteria, which vary based on the provider. Even if you don’t qualify under your insurer’s rules, the cost of a genetic test has dropped significantly over the past decade, Larsen Haidle says, with some labs offering quality versions for about $250 out of pocket.

Once you get your results, it’s important to talk them over with a geneticist, genetic counselor or physician who is knowledgeable about genetics. They can help you interpret the report and better understand any increased risk.

Then talk to your doctor about the benefits and risks of the different steps you could take to protect yourself, whether it’s increased screening, going on a medication such as tamoxifen, or taking a more serious step such as a mastectomy.

Try to remember that if you carry an inherited mutation, that doesn’t necessarily mean you’ll develop cancer, says Douglas R. Stewart, M.D., a senior investigator in the division of cancer epidemiology and genetics at the National Cancer Institute.

“We don’t understand why some people do and some people don’t,” he says. “There could be other genes, environmental factors or maybe just luck.”

Either way, if you have an inherited mutation, you should tell your family that they may be at risk, Pal says. Your children and siblings each have a 50 percent chance of having the same variant, and if so, there’s a 50 percent chance they will pass it on to their children.

“Sometimes the grandparent generation is a little bit more nervous about putting a burden on the kids and grandkids,” Larsen Haidle says. “Try to think of it as an empowering gift to help keep your family members healthy and reduce the risk they will be caught off guard by cancer.”

Michelle Crouch is a contributing writer who has covered health and personal finance for some of the nation’s top consumer publications. Her work has appeared in Reader’s Digest, Real Simple, Prevention, The Washington Post and The New York Times.