An estimated 266,000 women and 2,500 men will be diagnosed with breast cancer this year alone, and up to 10% of these may be hereditary. That’s over 26,000 patients and families whose lives could be significantly impacted by genetic testing, which can help guide personalized risk counseling and medical management.

Multigene panels, like BreastNext, can help you identify and manage patients with hereditary cancer by analyzing genes that are known to be associated with an increased risk for breast and other cancers.

Here we are answering 3 common questions about genetic testing for hereditary breast cancer:

1. How do I know who needs genetic testing?

The first step to determining who may need genetic testing is learning about your patient’s family history. Ask about at least 3 generations, all types of cancer, and ages at diagnosis. Next, you can use genetic testing criteria, such as the National Comprehensive Cancer Network guidelines, to figure out who to test. We have various tools and questionnaires available to help you with this process.

Some signs to look for include:

• Early onset cancer
• Multiple primary cancers in one person
• Rare types of cancer (such as ovarian or male breast cancer)
• Multiple people on the same side of the family with the same or related types of cancer

While genetic testing criteria are not available for every gene, BRCA1/2 criteria may help to identify patients with mutations in other breast cancer genes. We conducted a study of >89,000 patients undergoing multigene panel testing and found that BRCA1/2 testing criteria can help to identify patients with ATM, CHEK2, or PALB2 mutations¹.

2. What types of results can I expect?

There are 3 main types of results from genetic testing.

1. Negative: The majority of patients will fall into this category, since most cancer is sporadic. For these patients, medical management recommendations should be based on personal and family history.
2. Variant of Unknown Significance (VUS): This type of result means we found a variation in one of your patient’s genes, but there is not enough information available to determine if this is normal variation or disease-causing. A patient’s medical management should not be changed based on this type of result. Management should be based on personal and family history. Ambry will continue searching for clarity, and you will get an updated report if something changes that may impact your patient’s care.
3. Positive: While it varies by test and patient history, we expect about 10% of results to be positive. This means we found a variation in one of your patient’s genes that we know causes an increased risk for one or more types of cancer. In this case, additional cancer screening or preventive options may need to be considered. (See Question 3!)

3. What do I do if I get back a positive result?

Patients with a positive result may need to consider earlier and more frequent breast cancer screening, as well as additional types of screening, such as breast MRI. Some women may even consider preventive surgery, which can reduce their risk for breast cancer by >90%. You can refer to guidelines from the National Comprehensive Cancer Network and other sources to determine how to best care for your patient. Ambry’s positive results include “Clinician Management Resources” (if guidelines are available), so that the appropriate management recommendations are at your fingertips. Additionally, family members of someone with hereditary cancer may also be at an increased risk, so talk to your patients about who in their family may benefit from genetic testing.

Learn more about BreastNext, so that you can find answers for your patients and their family members.

1. Horton C et al. BRCA1/2 testing criteria offer high clinical sensitivity for ATM, PALB2 and CHEK2 carriers in a multigene panel cohort. Poster Presentation. ACMG 2018.