Guidelines for genetic testing in people diagnosed with breast cancer

Up to 10% of people diagnosed with breast cancer have an inherited mutation that caused their cancer. There are national guidelines that outline who should consider genetic counseling and testing for an inherited mutation linked to cancer.

Genetic testing for women diagnosed with breast cancer

All women diagnosed with breast cancer at age 45 or younger would benefit from genetic counseling and testing. 

Women diagnosed with breast cancer between ages 46-50 would benefit from genetic counseling and testing if they have any of the following: 

• a small family.
• unknown family history.
• cancer in both breasts or a second breast cancer in the same breast.
• 1 or more first-, second- or third-degree relative who have been diagnosed with any of the following:
  • ovarian cancer.
  • breast cancer. 
  • male breast cancer.
  • pancreatic cancer.
  • prostate cancer.

Women are likely to benefit from genetic counseling and testing if they were diagnosed with breast cancer at any age and have any of the following:

• triple-negative breast cancer.
• a relative who has tested positive for an inherited mutation associated with cancer.
• Eastern European (Ashkenazi) Jewish ancestry. 
• 1 or more first-, second- or third-degree relative who have been diagnosed with any of the following:
  • ovarian cancer.
  • breast cancer before age 50.
  • male breast cancer.
  • pancreatic cancer.
  • metastatic prostate cancer.
• 2 or more first-, second- or third-degree relatives with breast cancer or prostate cancer at any age
• 3 or more separate diagnoses of breast cancer in patient and/or close relatives combined.
• lobular breast cancer with a personal or family history of diffuse gastric cancer.
• metastatic breast cancer to determine eligibility for treatment with the targeted therapies Lynparza or Talzenna.
• early stage breast cancer at high risk for recurrence to determine eligibility for maintenance therapy with the targeted therapy Lynparza.

Women with the following are unlikely to have an inherited gene mutation:

• Diagnosed with breast cancer after 65 who have:
  • no prior history of breast, ovarian or pancreatic cancer.
  • no first-,second-, or third-degree relative who was diagnosed with breast, ovarian, pancreatic or prostate cancer.  
  • no Eastern European Jewish ancestry.

Genetic testing for men diagnosed with breast cancer

All men with breast cancer meet national guidelines for genetic counseling and/or testing, regardless of age at diagnosis.

Other people who may benefit from genetic counseling and testing

You may benefit from additional genetic counseling and expanded genetic testing if you had genetic testing in the past, you tested negative, and the following applies to you:

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

Breast cancer survivors and those in treatment should speak with a genetics expert to see if testing is right for them. 

Genetic testing for relatives of people who have been diagnosed with breast cancer

Genetic counseling and testing is also recommended for anyone with a first-degree or second-degree relative who meets the criteria listed above. 

See our sections Testing Guidelines by Cancer Type and Genetic Testing for People Who Have Never Been Diagnosed with Cancer for additional guideline information.