What is breast cancer?
Breast cancer is a disease that causes the breast to become abnormal, where cells grow without control to form a tumor. At its earliest stage, breast cancer does not usually have any symptoms, and does not cause pain. In later stages, the a lump or thickening may become visible and the breast may change size or shape. Other symptoms may involve the nipple discharging, becoming tender or turning inward. The skin on the breast may also become irritated, dimpled, or scaly. In later stages, the cancer can spread to other parts of the body, and lead to more serious health problems.
Although far more common in women, breast cancer can develop in men. Some types are more common in families who carry a genetic risk of developing the disease. These are known as hereditary breast cancers. Hereditary breast cancers tend to develop earlier in life are more likely to develop in both breasts.
Breast-conserving surgery (BCS), mastectomy, medication, radiation therapy, chemotherapy, and hormone are the most common and effective treatments for breast cancer. Some individuals with a stronger genetic risk of developing breast cancer chose to have pre-emptive surgery.
What is the genetic test?
Genetic testing allows us to identify people with a risk of developing hereditary breast cancer. The two genes most closely linked to breast cancer are BRCA1 and BRCA2. People with known genetic risk factors in BRCA1 or BRCA2 have a much greater chance of developing breast cancer, and have a 40%-80% risk of developing the disease. These genes are also associated with a greater risk of developing ovarian cancer, prostate cancer, and pancreatic cancer. Although BRCA1 and BRCA2 are most strongly linked to breast cancer, there are many other genes that are associated with increased risk, and for which genetic tests are also available.
How will this affect my health care?
If testing shows that you may have a genetic difference that increases your risk of getting breast cancer, it is important that you talk with your doctor or genetic counselor as soon as you can. There are a number of treatment and health management options available to you, and you may also want to think about family members that might also be at risk.
Who is at risk?
By 70 years of age, a woman in the United States, has about a 1 in 12 chance of developing breast cancer in her lifetime. Women who have an a faulty BRCA1 or BRCA2 gene can have about about a 7 in 12 chance of developing breast cancer. Women are a lot more likely breast cancer gene if they:
- Have a relative in either their mother's or father's family who had breast cancer or ovarian cancer.
- Have a relative with triple-negative breast cancer.
- Have a relative in either their mother's or father's family who had other cancers such as prostate, melanoma, pancreatic, stomach, uterine, thyroid, colon, and/or sarcoma.
- Are of Ashkenazi Jewish (Eastern European) ancestry.
- Have a family member with a known abnormal breast cancer gene.
Does my ancestry affect my risk?
Yes, people with Ashkenazi Jewish (Eastern European) ancestry are at increased risk. People with Hispanic ancestry are also at increased risk.
What are the treatments for breast cancer?
Breast-conserving surgery (BCS), mastectomy, medication, radiation therapy, chemotherapy, and hormone therapy are the most common and effective treatments for breast cancer. About 3.1 million women living in the United States have had breast cancer and survival after five years is more than 90%. For women diagnosed with localized breast cancer, the 5-year survival rate is over 98%.
A majority of women diagnosed with early-stage breast cancer (stage I or II) breast cancer, 59% have breast-conserving surgery, which is often combined with radiation therapy alone or with both radiation therapy and chemotherapy. Women with late-stage breast cancer (stage III or IV) are more likely to have a mastectomy (59%), and again this is commonly combined with radiation therapy or a combination of both radiation therapy and chemotherapy.
Can breast cancer treatments cause any problems?
Most of the treatments used to treat breast cancer have side effects. The Resources includes several sites where you can explore these effects in greater depth. As always, your doctor or health care professional can offer you guidance on what to expect from treatment, and you should be sure to ask lot of questions.
Why do a genetic test?
Some people are more likely to develop breast cancer because they inherited a faulty gene that causes it. Genetic testing tells us who is most at risk for developing breast cancer. Testing for certain genes is particularly important if they are considered to be 'medically actionable' - meaning test results can be used to improve health care.
In the embedded video, Dr. Dan Roden of Vanderbilt University discusses how genetic testing has begun to influence treatment of patients, particularly in relation to cancer.
What is the test?
There are many types of genetic tests for breast cancer. All genetic tests look at your DNA to try to identify faulty genes previously associated with breast cancer.
Many of the people who use this website are patients in hospitals who are part of the eMERGE network. These hospitals are using DNA sequencing to test patients for a number of diseases, including breast cancer, as recommended by the American College of Medical Genetics and eMERGE network members. Test results found to be medically ‘actionable’ (meaning they can be used to in patient health care) will be returned to patients.
Other types of testing for breast cancer include mammography, clinical breast exam, and breast MRI. This website does not have information on these tests, but you can find out more about them under Resources.
I am concerned whether I should be tested or not, what should I do?
The decision to be tested might be one of the most important decisions you have to make. There are many things you may want to consider. For some people, genetic testing can have positive health benefits, while others may feel a lot of stress and worry. You can read more about these issues in the Concerns & Risks section. It may help to think about testing for a while before making a decision. You may also find it helpful to discuss issues with those close to you, or with your doctor/health professional.
What will the test result mean?
This test will tell your doctor whether you are at increased risk of developing cancer, as well as a number of other diseases, as recommended for testing by the American College of Medical Genetics and the eMERGE network. If you are found to be at risk, your doctor or genetic counselor should help you understand your health care options.
What happens if I am found to be at risk?
If you are found to be at risk for any of the diseases that we test for, a health professional at your local site will attempt to contact you as soon as possible. Once we contact you, your doctor or genetic counselor should help you understand your health care options.
What happens if I am NOT found to be at risk?
If you are found NOT to be at risk for any of the diseases that we test for, you will likely NOT be contacted. However, a small number of patients may receive a medical report with results, while other patients may be re-contacted about another research study
If you have not been rec-contacted, please DO NOT ASSUME that you have been tested. There are a number of reasons testing may not have happened yet. For example, studies can sometimes take a very long time to complete, and DNA samples are often not usable because of quality-control issues.
How is the test being performed?
Testing is performed on your DNA, usually from a blood sample. For many patients, your hospital or treatment center may already have some of your DNA stored in a biobank. You may be asked for an additional sample or be asked to give us permission to do testing on the existing samples.
Will it hurt?
For some patients, we may need an additional blood sample. Taking blood may cause some pain, bleeding or bruising at the spot where the needle enters your body. Rarely, taking blood may cause fainting or infection.
Is it safe?
There is a risk that you may experience pain or bleeding if you need to give an additional blood sample. Risks concerning privacy are discussed under Concerns & Risks.
How long will I have to wait for results?
Unfortunately, we cannot give an accurate estimate for the time you will have to wait for results - this will depend on the resources available at the location where you receive treatment and were tested.
Is this a standard test?
Although increasingly more common, this test is not yet standard, and is typically offered as part of a research study.
What type of test is this?
- Is this test intended to help make a diagnosis? Yes
- Is this test intended to predict a family history of disease? Yes
- Is this test intended to check if I am a carrier for a particular disease? Yes
- Is this test intended to screen for genetic disorders? Yes
- Is this test intended to screen for disorders related to pregnancy? No
- Is this test intended to screen for disorders related to newborns? No
Will I need to have this test done more than once?
No, you should not need to have this test done more than once. You will need to keep track of your testing result in order to share with all of your doctors, including those you see at other medical care centers.
Will my genetic test results affect my family?
Your genetic test results may affect your family. In the embedded video, Maureen Smith, a researcher at Northwestern University, recommends first discussing genetic test results with your doctor. Your doctor may refer you to a genetic counselor, who can help you understand test results and guide you toward brochures and websites that can provide information for both you and your family.
- Before your genetic test: Because genetic information is inherited, it is important to be aware that your genetic test results are often relevant to your family members as well. Results may indicate that you are at risk, or that you are a carrier (see below). Before you have a genetic test, it can be a good idea to think about if and how you would like to share results with your family. Your doctor or genetic counselor should be able to provide more information about this.
- After your genetic test: For many of the diseases we test for, genetic test results may be relevant to your family members, as well as to you. You may be at risk, and you may be a carrier (see below). If you already have results, it is again important to think about sharing them with family. Again, your doctor or genetic counselor should be able to offer advice on how genetic testing may affect your family members.
Can you (briefly) explain heritability?
We each have about 24,000 genes, which carry the instructions for making and maintaining our bodies. For each gene we typically have two copies – one inherited from each parent. If genetic test results suggest you are at risk of developing a heritable disease, you will have inherited the risk from one or both your parents. Your brothers, sisters, children, parents, and other relatives may also be at risk of developing the same disease.
There are several ways we can inherit a genetic disease, which relates to whether it is recessive or dominant.
- For a dominant condition, only one copy of a gene needs to be faulty to cause a disease. In this case, if you have one copy of a faulty gene, you may be at high risk of developing the disease. You could pass this faulty gene to one your child or children.
- For a recessive condition BOTH copies of a gene must be faulty to cause a disease. In this case, if a person has only one copy of a faulty gene, they may not be at much greater risk. However, they may pass the faulty gene to their children. Again, this person is called a carrier.
Please note that the Resources section provides links to a number of websites that provide a much more detailed explanation of inheritance! Learn.Genetics at the University of Utah have a much more detailed explanation, which we find quite good – you can check it out here.
What is a carrier?
As described above, each of us has two copies of each gene. For recessive genetic conditions, BOTH copies of the gene need to be faulty for the person to be at risk of developing the disease. If a person inherits one faulty copy and one normal copy, they are called a carrier. Although they should not be at greater risk, they may pass the faulty gene copy to their child or children. If they do, and the child also inherits a faulty gene copy from the other parent, that child will be at risk of developing the disease.
What family members could be affected?
If a person had been found to be at risk, it makes the most sense to begin by testing the relative most closely related to them. Here are some examples:
- An aunt: If your mother's sister has an abnormal genetic test result, the next person to be tested would be your mother. If your mother is not found to be at risk (i.e. she tests negative), then you do not need to be tested, because she could not have passed the mutation on to you. However, if your mother's test is at risk (she tests positive), you might then decide to be tested. Finally, if your mother was not able to be tested, then you might also want to go ahead with testing based on your aunt's test result.
- A brother or sister: If a brother or sister has an abnormal test result (i.e. he/she tests positive) that increases his/her risk of developing a heritable genetic disorder, they will have inherited from one or both of your parents. If your parents have not already been tested, then they might want to consider doing so. Similarly, you and your other siblings might want to be tested. If you are at risk (test positive), you may pass that risk to your children.
My children are under 18 years of age – should they be tested?
Experts differ on whether children should be tested for risk of developing genetic disease. Their answer will often depend on the disease. The American College of Medical Genetics recommend testing children for most of the diseases listed on this website. For several of these diseases, no effective therapies exist until the child becomes an adult:
- Some experts believe that if genetic results will not affect a child’s health care until they become an adult, they should not be carried-out. They may also point out that children are not yet old enough to decide for themselves whether they want such information.
- Other experts believe that even if genetic results cannot affect a child’s health care until later in life, they should be carried out, as the test results may help the child make informed health care decision when they do become an adult. They may also point out that the opportunity to perform the genetic test may not arise again.
What Should I Do If I Have Concerns About Genetic Test Results?
If you are concerned about genetic test results you have received, you should discuss your concerns with your doctor. Your doctor should be able to explain results to you, and may recommend you to a genetic counselor or another doctor that can further help you understand your results. Maureen Smith, a researcher at Northwestern University, discusses these concerns in the embedded video.
Is there a reason why I may be a specific risk?
For most of the disorders discussed on this site, the American College of Medical Genetics recommends genetic testing for individuals with available genetic data.
Are there any implications for having children?
Yes, please see the Family Section
Can I expect to experience emotional consequences related to my test result?
A range of reactions are possible and normal. Some patients may experience anxiety or other negative reactions related to genetic testing. If this is the case, please discuss with your doctor, who can address your concerns and refer you another health professional if required.
Can I expect to experience social consequences related to my test result?
Some people may feel that there is a stigma attached to having a genetic disease. If you do experience or anticipate any negative social reactions, please discuss with your doctor who can address your concerns.
Can I expect to experience an increase in anxiety?
Many individual experience increased anxiety related to genetic testing. Again, please discuss with your doctor if this is the case.
Are there any implications in terms of discrimination arising from the test result?
Health insurance companies are prevented by law from discriminating against you based on your genetic test results. However, the same law does not apply to long-term disability insurance or to life insurance. Maureen Smith, a researcher at Northwestern University discussed these issues in the embedded video.
If I am found to be at increased risk for developing a disease, are there similar health implications for my family?
Yes, your results may have similar health implications for your family. Please see the Family section.
Should I tell other health care providers about my test result?
We do recommend that you share your health information with your doctor. However, as explained by Maureen Smith, a researcher at Northwestern University, what you decide to do with your results is up to you.
Who will see my test results?
People who have access to your medical record will be able to see your genetic test result. This may include health professionals such as doctors, nurses, pharmacists, and genetic counselors. However, health professionals from other centers or hospitals will likely not have access to your results.
Should my other family members be tested?
If you are found to be at risk for a heritable genetic disease, your family may also be at risk. We discuss this further in the Family section.
Will this affect my health insurance?
No, your health insurance will not be affected by this test result. However, as discussed below by Maureen Smith, a researcher at Northwestern University, your life insurance and other areas may be affected.
Who can I contact if they have any more questions?
You can contact your local center, where you received the test. The Resources section also includes a lot of websites that we recommend..
Is it there a risk to my privacy?
Research that uses information from medical records and that involves genetic testing can affect your privacy. Your participation in this research will be held strictly confidential, and only coded numbers will be used to identify specimens and research records. While it is impossible to absolutely guarantee that information in our secure system will never be known by others, we are taking every possible precaution to see that this does not happen.
We are compiling a list of websites to help you understand genetics and genetic test results. If you would like to suggest other resources for this section, please feel free to connollyj1 [at] chop.edu (send us an email)!
INFORMATION ABOUT CANCER:
About Cancer from the NCI
Fantastic resource all about cancer from the National Cancer Institute.
Direct link to the Breast Cancer pages at Cancer.Net. Very useful collection of resources and detailed information for patients with breast cancer, and their families
The Surveillance, Epidemiology, and End Results (SEER) Program
The Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute works to provide information on cancer statistics in an effort to reduce the burden of cancer among the U.S. population.
The Susan G. Komen Breast Cancer Organization
Large online resource, with facts and figures about breast cancer, treatment, and research.
Breastcancer.org is a nonprofit organization that aims to help women and their loved ones make sense of the complex medical and personal information about breast health and breast cancer.
INFORMATION ABOUT GENETICS AND GENETIC TESTING:
Genetics Home Reference
Consumer-friendly information about the effects of genetic variations on human health. Federally-supported resources, include reviews of more than 800 genetic diseases and more than 1000 genes.
Learning Resources from the NHGRI
Lots of very good resources from the NHGRI, including major sections about The Human Genome Project, Facts Sheets, and educational resources for teachers and students.
Find a Genetic Counselor
The National Society of Genetic Counselors have a searchable database of genetic counselors. Their website also includes some education materials for patients and healthcare professionals.
NHGRI Talking Glossary
Talking glossary of genetic terms developed by the National Human Genome Research Institute. A huge range of definitions is provided by researchers from around the world.
Help Me Understand Genetics
Help Me Understand Genetics is a handbook from the National Institutes of Health that contain useful information about genetics in clear language and provides links to even more online resources. The entire handbook can also be downloaded as a pdf.
Genetic and Rare Diseases Information Center (GARD)
A joint project from The Office of Rare Diseases Research (ORDR) and the National Human Genome Research Institute (NHGRI) that provides searchable information about genetic conditions and rare diseases. It also includes a list of FDA-Approved drugs and other medical products for treating rare disease.
National Organization for Rare Disorders - Resources for Parents/Families
The National Organization for Rare Disorders (NORD) is a volunteer organization dedicated to empowering the rare disease community. Again, they have some very nice web resources.
Ethical, Legal and Social Implications Research Program
The ELSI Research Program supports examinations and investigations of the ethical, legal and social implications of genetics research.
Genetic Information Nondiscrimination Act of 2008
The Genetic Information Nondiscrimination Act of 2008, also referred to as GINA, is a new federal law that protects Americans from being treated unfairly because of differences in their DNA that may affect their health.
Learn.Genetics, University of Utah
Excellent resources, especially for those involved in education. Includes a catalog of animations, videos, interactive features, and virtual labs.
Dolan DNA Leaning Center
The DNALC provides genetics learning resources for teachers and students.
INFORMATION FOR RESEARCHERS:
ClinVar: ACMG Recommendations for Reporting of Incidental Findings in Clinical Exome and Genome Sequencing
Clinvar's dedicated ACMG page - a useful jumping-off point to the Genetic Testing Registry, OMIM, MedGen, and local ClinVar pages for each gene.
N Petrucelli et al. Gene Reviews: Breast Cancer (updated September, 2013)
What is the purpose of this information?
Our aim is to provide information about why we do genetic testing. We try to answer some common questions and offer guidance on some personal and practical issues. This information is for anybody with questions about genetic testing for any of the diseases and drugs listed in this site.
Are there geographical differences in testing, service or treatment?
Different centers have different policies in terms of how tests are administered and results shared. However, the results discussed in this document should be relevant to most individuals tested for risk of developing genetic disease.
How is this paid for?
If you received this test as part of the eMERGE research study, neither you nor your insurance company will have to pay anything toward this test
When was this content last updated?
June 20, 2016.