Understanding genetic test results

A positive inherited genetic test result can change your annual screening plan and your family members’ health decisions. If you’ve been diagnosed with breast cancer, testing positive for certain mutations can change your treatment plan.

Several weeks after your genetic test, your doctor or genetic counselor will receive results. They will schedule an appointment to go over the results with you in detail. Together, you will discuss what the results mean for your risk of future cancers, and next steps to take.

Results may be:

• Positive: A positive result means you have an inherited gene mutation associated with cancer risk. A genetic counselor can help you understand what this means for you and for family.
• Negative: A negative result means that no mutations associated with increased cancer risk were found in any of the genes tested.
• Variant of uncertain significance (VUS): This result means a variant—a DNA change that may not always cause disease—was found. A VUS may or may not be associated with cancer risk. VUS results are common and do not typically affect your medical care.

If they have not already shared a copy with you, make sure to ask your genetic counselor or your oncologist for a copy of your genetic test results. You have a right to receive a copy. Having a copy can also help when you’re sharing results with family members and other healthcare providers.

Below, we’ll explain more about the possible test results and what they mean.

If you have never been diagnosed with breast cancer and test positive for a breast cancer-related gene mutation or are considering getting tested, visit At high risk for breast cancer.

Testing positive for an inherited BRCA mutation

Mutations in the BRCA1 and BRCA2 genes are the most well-known inherited breast cancer-related gene mutations.

Visit our Inherited BRCA mutations page to learn more about:

• Signs breast cancer may be BRCA-related
• Understanding BRCA genetic test results
• Next steps after getting your results
• PARP inhibitors for BRCA-related breast cancer treatment

Testing positive for other inherited genetic mutations

BRCA1 and BRCA2 are not the only inherited genetic mutations linked to an increased risk of breast cancer. There are also many others, including ATM, BARD1, PALB2, TP53, and more listed below.

The American Society of Clinical Oncology (ASCO) recommends that certain people be tested for mutations in these genes if it can help with:

• Decisions about treatment
• Managing the risk of a new cancer
• Confirming personal and family risk

Here is a list of currently known non-BRCA inherited mutations that increase the risk of breast cancer:

• ATM: The ATM gene works to prevent cancer. Inherited ATM mutations increase the lifetime risk of developing breast cancer. This mutation increases the risk of a second breast cancer in people who’ve already been diagnosed.
• BARD1: The BARD1 gene works with the BRCA1 gene to prevent cancer by repairing DNA. An inherited BARD1 mutation increases the risk of breast cancer.
• CDH1: The CDH1 gene plays a role in helping young epithelial cells (cells that cover and line many different parts of the body) develop into specialized, mature epithelial cells. Most breast cancer tumors start in epithelial cells. An inherited CDH1 mutation increases the lifetime risk of developing breast cancer and a stomach cancer called diffuse gastric cancer.
• CHEK2: The CHEK2 gene works to prevent cancer, and an inherited CHEK2 mutation can increase the lifetime risk of breast cancer. In people who have already been diagnosed with breast cancer, an inherited CHEK2 mutation increases the risk of a second breast cancer in the opposite breast.
• PALB2: The PALB2 gene works with the BRCA2 gene to prevent cancer by repairing DNA. An inherited PALB2 mutation increases lifetime risk breast cancer. In people who have already been diagnosed, these mutations increase the risk of a second breast cancer in the opposite breast. Inherited PALB2 mutations are also associated with a risk of ovarian cancer and pancreatic cancer.
• PTEN: The PTEN gene plays a role in how quickly cells divide. An inherited PTEN mutation increases the lifetime risk of developing breast cancer. Inherited PTEN mutations are also associated with a higher risk of thyroid, colorectal, endometrial, and kidney cancers as well as melanoma.
• RAD51C: The RAD51C gene works to keep cancer from developing. People with an inherited RAD51C mutation have an increased lifetime risk of breast and ovarian cancer.
• RAD51D: Like RAD51C, the RAD51D gene works to prevent cancer. An inherited RAD51D mutation increases lifetime risk of breast and ovarian cancer.
• STK11: The STK11 gene helps keep cells from growing out of control. Inherited STK11 mutations can lead to breast cancer in some people. This mutation is also associated with other cancers, including pancreatic, stomach, and colorectal cancers.
• TP53: The TP53 gene plays a role in cell division and cell death. People with an inherited TP53 mutation have an increased lifetime risk of breast cancer. In people who have already been diagnosed with breast cancer, an inherited TP53 mutation increases the risk of a second breast cancer in the opposite breast. Inherited TP53 mutations are also associated with a higher risk of cancers of the soft tissue, blood, bone, brain, and adrenal glands.

Risk percentage numbers for each of the above genetic mutations can change frequently as research changes. To find the latest percentage risks, visit Facing Hereditary Cancer Empowered (FORCE).

Talking with your healthcare team about positive results

If you test positive for one or more of these inherited mutations, a genetic counselor can help you understand your individual risk for breast and other cancers. It’s important to talk with your genetic counselor and oncologist about:

• Whether testing positive affects your annual breast cancer screening plan. For example, your doctor may recommend adding an annual MRI or other imaging tests to your plan.
• Whether there is an increased risk for a new breast cancer in the other breast. If there is, ask about risk-reducing options such as increased screening and/or prophylactic mastectomy.
• Ways to lower your individual risk of breast cancer. Risk is highly individual and based on your genetic test results, characteristics of your diagnosis, and your medical history. Risk-reducing strategies may be different for you than they are for others you know with gene mutations.
• Clinical trials studying breast cancer treatment in people who test positive for one of these mutations. Participating in a clinical trial is a great way to get treatment while supporting research. Right now, there are no FDA-approved treatments that specifically target breast cancers in people with these inherited mutations. Joining a trial helps in their future development. If you’re interested in finding a trial, ask your genetic counselor or oncologist for information.

Testing positive and your emotions

Positive genetic test results can trigger a range of emotions—relief that a family history now has an explanation, or fear about a future cancer for you or your family. It’s normal to feel worried about whether family members may also carry the same mutation. There’s no right way to respond to a positive result, and you do not have to go through it alone.

Let your genetic counselor or your oncologist know if you need help. They can refer you to support resources, including mental health professionals, peer-to-peer support groups, and organizations such as FORCE, where you can meet others who have also received a positive result.

If you don’t have access to a genetic counselor, ask your care team for a referral to the hospital social worker or nurse navigator.

To learn more about sharing the news with family, visit Sharing your genetic test results.

Testing negative

Like testing positive, testing negative for an inherited genetic mutation can come with many feelings. You might feel better knowing you can’t pass a mutation on to your children or grandchildren, or you might feel disappointed when a negative result doesn’t provide clarity about why you may have been diagnosed with breast cancer.

If you have a personal or family history of breast cancer and are the first in your family to have genetic testing, a negative result may mean several things, such as:

• You tested negative for inherited high-risk genetic mutations known today, but you may carry an inherited mutation that current testing cannot identify.
• If you do not have a personal history of cancer, there is still a chance that family members have a hereditary cancer mutation that you did not inherit. Often, testing for family members who’ve had cancer can be more informative and help you and your counselor better interpret your test results.
• Additional genetic testing may be recommended if the test you had focused only on certain genes.

Your genetic counselor will help make sense of the results and how they relate to your personal and family history.

When tests find no inherited genetic mutation in a family with a long history of breast cancer, negative test results need to be interpreted with caution. We know that known mutations do not explain all hereditary patterns of breast cancer.

If results are negative, you may still be eligible for more frequent or additional screenings or other risk-reducing options based on personal and family history alone. Talk with your counselor and your oncologist about next steps.

A true negative test result

If you get a negative result and your genetic test was looking specifically for a genetic mutation someone in your family has already tested positive for, this is considered a true negative test result.

Getting a true negative result means:

• You have the same risk of a future breast cancer as any woman diagnosed with breast cancer who has no inherited genetic mutation.
• Your screening schedule and treatments will be based on the characteristics of your diagnosis, your age, and other factors.

A result your provider calls uninformative negative

If you have a strong family history of breast cancer but no mutations were found in the genes tested, your genetic counselor or oncologist may refer to your negative genetic test result as uninformative negative.

This term is often used when there is still high suspicion for a hereditary cancer risk in your family. There could still be an inherited genetic mutation that is not yet possible to find with current testing.

If your genetic counselor or oncologist says that your result is uninformed negative, ask them about next steps that are right for your individual level of risk.

A variant of uncertain significance (VUS)

Although there are known disease-causing (pathogenic) genetic variants associated with a higher risk of breast cancer, not all variants identified in a genetic test cause cancer.

If your results come back with a variant of unknown or uncertain significance (VUS), it’s important to know that these are common and usually are not cause for concern. They should not be used to inform medical care.

A variant of uncertain significance means a change was found in one of your genes. However:

• It is not known whether the variant increases the risk of cancer.
• It could just be a unique difference in the gene that has no impact on your health.

You may learn more about the VUS if other people in your family are tested and as research on that variant continues.

VUS results are common and are not typically used to guide decisions about your care. Most VUS results turn out to be harmless. Still, it’s important to check in with your healthcare team for updates as more research is done.

As with a negative test, if you have a strong personal or family history of breast cancer, talk with your oncologist about your options for reducing the risk of a new cancer.

What genetic test results may mean for your family

Because inherited gene mutations are passed from parents to children, your test results may have a direct impact on members of your family.

If you test positive:

• Each of your children has a 50% chance of inheriting the mutation, whether male or female.
• Any first-, second-, and third-degree relatives, both men and women, are at higher-than average risk of developing cancer. They should consider meeting with a genetic counselor to discuss testing.
• It is recommended that the most closely related family members, such as parents, siblings and children, be tested first, to find out which other family members are most likely to inherit a mutation.

If test results are negative or uncertain, or if your provider says your result is uninformative negative, each member of your family should follow an individualized screening plan. Their doctors or a genetic counselor can tell them if they should follow high-risk screening standards.

Talking with family about genetic testing can sometimes be difficult. Your family members may or may not want to know their own results or may have strong opinions about how you handle yours. For tips on how to talk with family about test results, visit Sharing your genetic test results.