What to Know About Genetic Testing for Breast Cancer

If you or a family member has had breast cancer, you could qualify for genetic testing. Here’s what to know. 

Breast cancer screening is a routine part of preventive health. There are several known genes that increase your risk of breast cancer. If you or a direct family member (mother, sister, daughter, aunt, grandmother) has had breast cancer, particularly if they were diagnosed under age 50, you might have one of the genetic mutations that puts you at a higher risk of developing breast cancer. 

“I recommend genetic testing for any patient with breast cancer,” says Julie Culver, LCGC, director of genetic counseling with the USC Norris Comprehensive Cancer Center, part of Keck Medicine of USC. At Keck Medicine, she adds, any patient who has had breast cancer or currently has breast cancer can be seen for genetic counseling and testing. Breast cancer patients may decide to use genetic information to influence surgical planning. Even older patients may benefit from the knowledge of genetic status, since it can influence treatment and prevention decisions, Culver says. Finally, many women with breast cancer also want genetic information to have on hand for their children.  

Additionally, Culver recommends getting tested if one of your direct family members (mother, sister, daughter, aunt, grandmother) had breast cancer before the age of 50 or ovarian cancer at any age. This is especially important if your family member with breast cancer tested positive for an inherited genetic mutation associated with breast cancer, such as those in the BRCA1 and BRCA2 genes. 

Here is how genetic testing can be approached for a woman without breast cancer but whose mother had breast cancer: “If your mother tests negative for any genetic mutation, then you as the daughter probably do not need to get genetic testing because there is no genetic mutation explaining the breast cancer,” Culver says. “But if your mom had genetic testing and she’s positive for a genetic mutation, then you, her daughter, should get genetically tested because there is a 50% chance you could also have the mutation.” 

What age should you get genetic testing for breast cancer if you have a relative with breast cancer?  

If there’s a known gene mutation within the family, a good time to get genetic testing done for breast cancer is between the ages of 21 and 25, Culver says. Under most settings, screening starts around age 25. Genetic testing ensures that if you do have a gene mutation, your doctors can optimize future screening schedules to monitor you closely, Culver says. For instance, if you do have a genetic mutation, your doctor might recommend that you start receiving breast MRI screenings around age 25. 

“And it’s never too late to get tested,” Culver adds. “If at-risk people are in their 50s, 60s and 70s, we still recommend doing genetic testing as long as they are healthy enough to undergo breast cancer screening.”  

What happens at a genetic testing appointment?  

The first step is a pre-test genetic counseling appointment. For Keck Medicine patients, this can be done either at USC Norris Cancer Hospital or remotely via telemedicine. At this appointment, a genetic counselor will take your family history and discuss genetic testing. If your appointment is conducted remotely, you have the option of having a mobile phlebotomist come to your home. If you are seen at USC Norris Cancer Hospital, the blood draw can be done on-site the same day at your appointment.  

“We ask you to come prepared to discuss your family history during the session,” Culver says. “A questionnaire is sent ahead of time, as well as assistance to help build your family tree online. This is really helpful because then you know the types of questions you’re going to be asked at your appointment.”  

Questions generally involve whether family members had cancer, what types of cancer they had, at what age they developed cancer and how old they are now. Your counselor then uses this information to create a family tree to understand if there’s a pattern of cancer in the family, whether it’s breast cancer or another type of cancer.  

“This helps guide the discussion about what genes could be explaining the family’s history of cancer,” Culver says. 

“When we meet with the patient, we also talk about their medical history because we want to be sure we’re addressing any concerns,” she adds. For instance, if you’ve had an abnormal mammogram or a concerning biopsy, or if you have a history of some kind of benign lesion, these facts are also taken into consideration.  

How many genes should I get tested for breast cancer?  

Patients of Keck Medicine generally get tested for a large panel of 70-85 genes for breast cancer. “We encourage people to get the large panel because we don’t want to miss an opportunity to identify any prevention opportunities,” Culver says. 

Does insurance cover genetic testing for breast cancer? 

“Most of the time, insurance plans are quite good at covering genetic testing,” Culver says. “That’s one of the myths we’re trying to dispel — that genetic testing is very expensive.”  

Genetic counselors can also offer an option for free testing through scientific foundations if insurance coverage is poor, she says. “We try to not let cost be a barrier, and provide options for everyone — especially people who are at high risk — to get genetically tested if they want to,” she says.  

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