Breast Cancer Genetic Testing

Why should people with breast cancer get genetic testing?

Genetic test results may affect your cancer treatment options, including allowing you access to newer therapies. 

• People who test positive for a BRCA1, BRCA2 or PALB2 mutation may benefit from treatment with a PARP inhibitor.
• People who test positive for a mutation in another gene may qualify for clinical trials looking at new treatments for breast cancer. 

Genetic test results may help you and your relatives understand the risk for cancer and take action to stay healthy. 

• If you test positive for an inherited mutation, you may have an increased risk for other cancers.
• Your test may allow relatives to learn if they are at increased or average risk for cancer. 
• Expert guidelines outline cancer screening and prevention options for people who test positive for a mutation linked to breast cancer risk.   

Should everyone with breast cancer get genetic testing?

Breast cancer survivors and those in treatment should speak with a genetics expert to decide if genetic testing is right for them. There are expert guidelines that outline who is most likely to benefit from genetic testing. 

Experts recommend genetic counseling and testing if you have breast cancer and any of the following applies to you:

• triple-negative breast cancer.
• diagnosed with breast cancer more than once. 
• breast cancer diagnosed at age 50 or younger.
• male breast cancer or assigned male at birth.
• advanced or metastatic breast cancer.
• early stage breast cancer and at high risk for recurrence to learn if there would be benefit to treatment with a PARP inhibitor.
• a close blood relative (first-, second- or third-degree) who tested positive for an inherited mutation in a gene linked to cancer risk.
• a close blood relative diagnosed with male breast cancer. 
• Ashkenazi Jewish ancestry.
• lobular carcinoma and a personal or family history of diffuse gastric cancer.

Experts also recommend genetic counseling and testing for people diagnosed with breast cancer at age 50 or older with any of the following:

• a close relative with breast cancer at age 50 or younger.
• a close relative with male breast, ovarian or pancreatic cancer.   
• a close relative with prostate cancer that is metastatic or high-risk or very high-risk group. 
• three or more close relatives on the same side of the family with either breast or prostate cancer (including the patient). 

If you had genetic testing in the past and tested negative, you may benefit from additional testing:

• if you had a test that only looked for one or a few genes, or 
• if you had genetic testing before 2014. Genetic testing has improved, and laboratories can now find gene mutations that may have previously been missed.

Should relatives of people with breast cancer get genetic testing?

Genetic counseling and testing is also recommended for anyone with one or more 1st- or 2nd-degree relatives with breast cancer and any of the following:

• diagnosed at age 50 or younger
• triple-negative breast cancer
• two separate breast cancers, with the first diagnosis at age 50 or younger
• male breast cancer

Which genes are linked to hereditary breast cancer?

Mutations in the following genes increase the risk hereditary breast cancer.

Are breast cancers in people with gene mutations different?

Some inherited mutations increase the risk for specific types or subtypes of breast cancer. 

How do I get genetic testing for hereditary breast cancer?

Genetic testing is a type of blood or saliva test performed on blood, saliva or tissue. The sample is collected and sent to a genetic testing lab. A doctor or nurse with expertise in genetics or a genetic counselor can help you get genetic testing. You can read more about the process here.