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

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

• a relative who has tested positive for an inherited mutation associated with cancer
• diagnosed at age 45 or younger with any type or stage of breast cancer (including DCIS), regardless of family history of cancer
• diagnosed at age 50 or younger and either:
  • a small family, or
  • limited information about their family's medical history  
• cancer in both breasts or a second breast cancer in the same breast
• triple-negative breast cancer before age 60
• Eastern European (Ashkenazi) Jewish ancestry 
• one or more relatives with breast, ovarian, pancreatic, prostate or melanoma cancer
• metastatic breast cancer.  Patients who test positive for a BRCA mutation may be eligible for treatment with the targeted therapies Lynparza or Talzenna.

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 has been diagnosed with:

• Breast cancer at age 45 or younger
• Two separate breast cancers in the same relative, with the first diagnosis at age 50 or younger
• Triple-negative breast cancer at age 60 or younger
• Male breast cancer

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