Breast Cancer Genetic Testing: What to Know Before You Go

Most people have heard of genetic testing for breast cancer, which can help determine if breast cancer in the family is hereditary. While many people are familiar with the BRCA1 and BRCA2 genes and cancer risks, there are several other breast cancer genes we can test, ensuring we are offering the most up-to-date testing and learning even more about someone’s cancer risk based on their DNA. In addition to genetic testing, we can also review a person’s medical and family history to recommend a personalized breast cancer screening plan. It is a common misconception that breast cancer comes from the mother’s side of the family, but you can also inherit a breast cancer risk gene from your father’s side of the family. We do not want patients to overlook the women on their father’s side, such as their grandmother, aunts, or cousins.

What Genetic Testing Options Are Available?

When ordering genetic testing, we usually test several genes at a time, which is called a panel test. We can run a smaller panel focused on a specific type of cancer, such as breast and ovarian cancer. We can also include more genes for people with multiple cancers in the family, or for people that want to learn more about what cancers they are at risk for based on their DNA. Right now, we can test up to 90 cancer genes, and that number increases as technology improves.

How Does it Work?

If you are interested in genetic testing, your doctor can make a referral, or you can self-refer by calling 513-853-GENE (4363) and asking for a cancer genetic counseling visit. Initially, you will meet with a genetic counselor who will review your medical and family history, which includes the following questions:

• Who in your family has had cancer?
• For relatives who have had cancer, what type of cancer was it and what age were they diagnosed?
• Was any breast cancer triple negative (ER, PR, Her2 negative)?
• Were any breast cancers bilateral or include two separate cancers?
• Have any men in your family been diagnosed with breast cancer?
• In addition to breast cancer in the family, are there any other cancers (such as ovarian, pancreatic, uterine, colon, prostate, etc.)? This can provide clues to other genes that may have a mutation.
• Do you have Ashkenazi Jewish ancestry?

From there, you will discuss genetic testing – the recommendations, benefits, limitations, and potential follow-up after testing. Testing is typically done through a blood draw and if you choose to proceed with testing, we can collect a sample the same day as your appointment. Results come back in 2-4 weeks. Once your results are back, your genetic counselor will call you to discuss next steps. You can also view your results on MyChart.

I've Tested Positive for a Gene Mutation: Now What?

Your genetic counselor will discuss the following with you:

• The mutation and the gene it is in
• The associated cancer risks
• Screening options, including types of screening, how often to do them and cancer prevention options.
• Referrals and specialists to meet with, as well as placing referrals.

As an example, someone with a mutation in a breast cancer gene (and an increased breast cancer risk) may be able to start breast cancer screenings at a younger age, as early as twenty-five. She may also be able to do more screenings, such as a breast MRI and a mammogram, switching between the two screenings every six months.

A lot of these genes are associated with multiple cancers, so there may be other cancer risks that people are not aware of, such as an increased risk for ovarian cancer, pancreatic cancer, melanoma, or colon cancer. Your genetic counselor will review the other risks and screening recommendations and work with you to create a personalized cancer screening plan.

I've Tested Negative for Gene Mutations: Now What?

While you are not at an increased risk of developing cancer based solely on your DNA, you may be at an increased risk based on your medical and family history. Your genetic counselor will review your family history to determine if there are any additional cancer screening recommendations you may consider.

For example, we can calculate your estimated risk of developing breast cancer based on information collected at your first appointment. For people that are at an increased risk, we can refer you to our High-Risk Breast Program. At this appointment, you will meet with a breast specialist to discuss ways to reduce your breast cancer risk, and they can also schedule a breast MRI and mammogram to improve the change for early detection when cancer is easier to treat and cure.

The goal throughout this process is to create a more personalized care plan that fits you based on your medical history, family history, and needs. For more information, you can visit the Precision Medicine page for Hereditary Cancer.