Do I Need Genetic Testing for Breast Cancer?

For more than 20 years, experts have recommended genetic screening for breast cancer for certain women who have a family history of breast or ovarian cancer. Now the U.S. Preventive Services Task Force says women who have survived breast or ovarian cancer (as well as peritoneal or fallopian tube cancer) and women with Ashkenazi Jewish ethnicity might also benefit from screening.

These women should talk to their primary care providers about genetic counseling and testing. “Primary care providers are recommended to look for ‘red flags’ for hereditary cancer,” says John Zimmerman, M.S., a certified genetic counselor at UT Southwestern Medical Center. These red flags include breast cancer diagnosed before age 50, multiple family members with breast cancer, the presence of breast and ovarian cancer in a single individual, and Ashkenazi Jewish ancestry. “The presence of these red flags should prompt a referral to a genetic counselor to discuss how genetic testing might help them.”

Making the Genetic Testing Decision

Two genes – BRCA1 and BRCA2 – are widely recognized for their link to breast and ovarian cancer, but there are many other genes that can play a part in cancer risk. “Genetic counseling can help women consider what testing options are best for them,” Zimmerman says, adding that some tests focus only on genes that are primarily linked with breast cancer while others are directed at different cancers. 

“Genetic testing is a very personal choice,” Zimmerman says. “There are implications to consider.” For example, some worry they will feel guilt at having passed a genetic predisposition along to a family member. Others might have concerns regarding how genetic testing results could affect life, disability, and long-term care insurance. “These are considerations to talk through with a genetic counselor to decide if genetic testing makes sense,” Zimmerman says.

Options for Women at High Risk

Genetic testing can help clarify the level of cancer risk a woman faces. Depending on the gene, a woman might face up to a 60% risk of breast cancer in her lifetime if she tests positive. Knowing her risk, a woman might take steps such as:

• Adding more breast cancer screenings at younger ages; for example, choosing breast MRI as well as mammography
• Reducing her risk with preventive surgery to remove breast tissue or the ovaries
• Following other cancer risk-reduction or prevention strategies, depending on the cancer risk discovered due to a gene mutation
• Informing her family members so they can decide if they want to be tested to evaluate their own risk

While direct-to-consumer genetic testing for breast cancer is available, it analyzes only a select few mutations in the BRCA genes. Zimmerman notes that confirmatory clinical testing is recommended for any mutations identified via direct-to-consumer assessment. “There are thousands of mutations in the BRCA genes and a number of other breast cancer risk genes. Direct-to-consumer testing is getting only a small part of the picture,” he says.

A genetic counselor can help women navigate genetic testing options to better understand their cancer risks and how to best manage these risks.