If breast cancer runs in your family, you may have questions about what that means for you and your loved ones.
Does having a family history mean you inherited an increased risk? Should you consider genetic testing? And what could the results mean for you or other members of your family?
Genetic counseling can help answer those questions. It gives you an opportunity to take a closer look at your personal and family history, understand whether hereditary cancer may be a concern, and decide whether genetic testing makes sense for you.
“We help patients make decisions that align with their interests and values,” said Christina Falugi, MS, CGC, a certified genetic counselor and director of Cancer Genetics at The University of Texas Medical Branch (UTMB Health).
Most breast cancers are not hereditary
Only about 5% to 10% of breast cancer cases are hereditary.
Most breast cancers are considered sporadic, meaning they develop because of genetic changes that occur over time rather than because of a mutation inherited from a parent.
Certain patterns can make a hereditary cause more likely, including:
- Breast cancer diagnosed at age 50 or younger
- Three or more relatives with breast cancer on the same side of the family
- Multiple related cancers in a family, such as breast, ovarian, prostate, and pancreatic cancers
- A family history of rarer cancers, such as ovarian or pancreatic cancer
- Cancer occurring across multiple generations
These patterns can help identify families that may benefit from genetic counseling and further evaluation.
What happens during genetic counseling?
One of the most helpful things you can bring to a genetic counseling appointment is information about your personal and family history of cancer.
Your genetic counselor may want to know:
- Which relatives have had cancer
- What type of cancer they had
- About how old they were when they were diagnosed
- Whether multiple cancers have occurred on the same side of the family
That information can help determine whether your family history suggests a hereditary cancer pattern and whether genetic testing may be appropriate.
It can also help your care team determine which genes may be most relevant to test and whether changes to your cancer screening or prevention plan should be considered.
Family history is not the same as hereditary cancer
Having several relatives with breast cancer does not automatically mean your family carries an inherited genetic mutation.
About 15% to 20% of breast cancer cases may be considered familial. That means breast cancer occurs in a family more often than expected, but the pattern does not necessarily point to a specific inherited cancer mutation.
In those families, risk may reflect a combination of shared environmental factors, lifestyle habits, and genetic factors that researchers are still working to understand.
Hereditary breast cancer is different. In those cases, a person is born with a specific genetic mutation that increases the risk of developing certain cancers.
Genetic counseling can help patients understand that distinction and what their family history may mean for them.
What does a positive genetic test actually mean?
You may have heard someone say they “tested positive for a cancer gene.”
That phrase can be confusing because everyone has genes associated with cancer. Many of these genes normally help protect the body by preventing abnormal cells or tumors from developing.
A positive genetic test means testing found a mutation in one of those genes that prevents it from functioning properly.
That can increase a person’s risk of developing cancers associated with that gene compared with someone in the general population.
But a positive result does not mean you currently have cancer, and it does not mean you will definitely develop cancer in the future, Falugi said.
Instead, knowing about an inherited mutation gives you and your care team information that can help guide screening, prevention, and treatment decisions.
How can genetic testing change your care?
If testing finds a mutation associated with increased cancer risk, the result can provide a clearer picture of which cancers you may be more likely to develop and what steps can be taken in response.
Falugi describes a positive genetic result as a “road map” that can help guide decisions about detecting cancer earlier or preventing it when possible.
For someone with an inherited mutation associated with breast cancer, that may mean beginning breast screening at a younger age or having more frequent screening with mammograms and breast MRIs.
For some patients with a very high inherited risk, risk-reducing surgery, such as removal of both breasts (bilateral mastectomy) with reconstruction, may also be considered.
Some genes associated with breast cancer are also linked to an increased risk of other cancers. Depending on the genetic result, your care team may recommend additional screening or preventive strategies for those cancers as well.
What could your results mean for your family?
Genetic testing can provide valuable information not only for you, but also for your relatives.
If testing identifies an inherited mutation, first-degree relatives, such as parents, siblings, and children, each have a 50% chance of carrying the same genetic change.
Sharing that information gives family members an opportunity to decide whether they want genetic counseling or testing of their own.
For relatives who also carry the mutation, learning about it earlier can make it possible to begin appropriate cancer screening or risk-reduction strategies sooner.
That can be especially important because hereditary cancers may develop at younger ages than cancers that occur sporadically.
Genetic counseling does not mean you have to get tested
Meeting with a genetic counselor does not commit you to genetic testing.
The purpose of counseling is to help you understand your individual risk and the options available to you.
A genetic counselor can explain:
- Whether your personal or family history suggests an inherited cancer risk
- What genetic testing can and cannot tell you
- The potential benefits and considerations of testing
- Insurance coverage for testing
- Screening recommendations based on your family history
- What a result could mean for you and your relatives
From there, you can decide whether testing is right for you.
The goal is to give you the information and support you need to make a decision that reflects your own concerns, priorities, and values.
Understanding your family history is a good place to start
If you are concerned about breast cancer in your family, start by gathering whatever information you can about relatives who have had cancer, including the type of cancer and their approximate age at diagnosis.
You do not need to determine on your own whether that history is significant.
A genetic counselor can help you understand what those patterns may mean, whether testing should be considered, and what screening or prevention steps may be appropriate based on your individual risk.
Knowing more about your family history does not predict your future. But it can help you and your care team make informed decisions about your health.
Learn more about cancer genetics and genetic counseling at UTMB Health.