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Genetic Testing For Breast Cancer How Is It Done

What Else Should I Consider Before Getting Genetic Testing

Updates in Genetic Testing and Breast Cancer

Working with a genetic counselor before making a decision may help you explore other, often-unanticipated consequences associated with genetic testing.

Emotional impact

Finding out you have an increased risk of cancer may cause stress and anxiety. It can sometimes change family relationships. Some may experience survivor guilt when they learn they didnt inherit the risk but family members they love did. Other times, those who inherited the risk wonder, Why me?

Potential discrimination

People sometimes wonder whether discovering an increased risk of cancer could affect their future and lead to discrimination when it comes to employability and obtaining life or health insurance coverage.

The federal law, Genetic Information Nondiscrimination Act of 2008, prohibits genetic discrimination by health insurers and in the workplace, but the law doesnt extend to life insurance, disability or long-term care.

What genetic testing cant tell us

Genetic test results cant tell us whether you have cancer at the moment of testing or whether youll ever develop it.

The results cant tell whether youre at risk for conditions that arent being tested, such heart disease, diabetes or stroke. Right now, most genetic testing is focused on a particular area of medicine. So when we coordinate genetic tests for people in the oncology setting, it’s only to look for inherited risks for cancer. We currently dont have a test that’s widely available to screen for all health conditions.

How Is Genetic Testing Done

Genetic tests are usually requested by a persons genetic counselor, doctor, or other health care provider who has reviewed the individuals person and family history. The genetic test options from which a health professional may select include those that look at a single gene and those that look for harmful variants in multiple genes at the same time. Tests of the latter type are called multigene tests.

Testing is done on a small sample of bodily fluid or tissueusually blood, but sometimes saliva, cells from inside the cheek, or skin cells. The sample is then sent to a laboratory that specializes in genetic testing. The laboratory returns the test results to the doctor or genetic counselor who requested the test. It usually takes several weeks or longer to get the test results.

Health insurance typically covers genetic counseling and many genetic tests, if they are considered medically necessary. A person considering genetic testing should discuss costs and health insurance coverage with their doctor and insurance company before being tested.

Risk Factors For Hereditary Cancer

A hereditary cancer is any cancer caused by an inherited gene mutation. An inherited gene means it is passed from parent to child within a family. The following factors suggest a possible increased risk for hereditary cancer:

Family history of cancer. Having 3 or more relatives on the same side of the family with the same or related forms of cancer.

Cancer at an early age. Having 2 or more relatives diagnosed with cancer at an early age. This factor may differ depending on the type of cancer.

Multiple cancers. When one relative develops 2 or more types of cancer.

Rare cancers. Some types of cancer, such as ovarian cancer, adrenocortical cancer, or sarcoma, are linked to inherited genetic mutations.

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How Does Genetic Testing For Breast Cancer Work

Genetic testing for breast cancer risk typically uses a sample of blood, saliva, or cells from the inside of your cheek. After the sample is collected, its sent to a lab specializing in genetic testing to be analyzed.

Several gene variations that increase breast cancer risk have been found. The most important are those in the BRCA1 and BRCA2 genes. According to the National Cancer Institute, about people have a harmful BRCA variation.

About of females with harmful BRCA1 and 45 to 69 percent of females with harmful BRCA2 variations will develop breast cancer by age 80. Their risk of getting breast cancer in the other breast is also higher.

Other gene variants that may raise breast cancer risk include:

Gene variations that can be detected may vary by test. For example, some tests may only cover the most common variations, while others may be more extensive.

Once your sample is submitted, youll receive your results in 2 to 4 weeks. A healthcare professional or genetic counselor will contact you and discuss your results.

Results you can receive include:

  • Positive: A known gene variation that increases your risk of breast cancer was detected.
  • Negative: A known gene variation that raises your risk of breast cancer was not detected.
  • Variant of unknown significance: A variant has been found in a gene, such as BRCA1 or BRCA2, but its impact on breast cancer risk is currently unknown.

How Genetic Testing Is Done

How Do Single

Genetic testing can be done on samples of blood or saliva, or from a swab of the inside of a cheek. The samples are sent to a lab for testing.

There are many different possible mutations in the BRCA genes. Testing can look for one specific mutation, or more extensive testing can be done to look for many different BRCA mutations. For example, if someone is being tested because they have a family member with a known BRCA mutation, testing might focus only on that specific mutation. In people of Ashkenazi Jewish descent, testing might focus on the specific BRCA mutations that are most common in this group of people. But if theres no reason to suspect a specific gene change, testing will likely look for many different BRCA mutations. Depending on the situation, testing might be done to look for changes in other genes as well.

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Less Common Altered Genes

Women with an altered PALB2 gene have a 4463% risk of breast cancer.


Women with an altered TP53 gene have an up to 85% risk of breast cancer.

The lifetime risk for a person with an altered TP53 gene to develop any type of cancer is 90%.


Women with an altered CHEK2 gene have a moderate risk of developing breast cancer.

Moderate risk is higher than the general population. However, its still more likely they will not get breast cancer.


Women with an altered ATM gene have a moderate risk of developing breast cancer.

Moderate risk is higher than the general population. However, its still more likely they will not get breast cancer.

Other genes

Some genetic conditions caused by rare altered genes are also associated with breast cancer.

These include:

  • Peutz-Jegher syndrome
  • Cowden syndrome/PTEN hamartoma tumour syndrome
  • Hereditary diffuse gastric cancer syndrome gene)
  • Neurofibromatosis type 1

If one of these runs in your family, your genetics team will talk to you about your risk of breast cancer.

Benefits Of Genetic Testing For Inherited Gene Mutations Related To Breast Cancer Risk

Genetic testing may give you information about your risk of developing another cancer, such as ovarian cancer or prostate cancer .

It may also help your family members better understand their risk of breast cancer and other cancers, such as ovarian cancer, prostate cancer or pancreatic cancer. In some cases, genetic testing may help tailor their cancer screening.

Talk with your health care provider or a genetic counselor about whether it would be useful to have genetic testing.

Learn more about genetic testing for inherited gene mutations related to breast cancer risk.

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What Does A Positive Gene Test Mean

A positive result means you carry a gene mutation that increases your risk of cancer and you can work with your doctor to manage that risk. A negative result may mean that you dont have the mutation or that you might have a gene mutation doctors havent discovered yet. Your test might also identify a gene variant that doctors arent certain about. In these situations, its not always clear what the results mean for your cancer risk.

What Are The Potential Benefits Of Genetic Testing For Breast Cancer

Genetic testing for breast cancer patients is becoming more common

When patients come to me for genetic counseling at CTCA®, most want to know how genetic testing might benefit them and/or their family members.

Genetic testing informs us about the risk of developing a future cancer, but results may also be useful in guiding cancer screening decisions, in taking risk-reducing measures and in treatment decisions for those whove already been diagnosed with cancer.

With or without a cancer diagnosis, test results may help a person and his or her family members understand their risk of developing certain future cancers and allow them the opportunity to take steps to reduce their risk or to be more proactive about cancer screening.

For example, patients who know they have a mutation may consider more frequent screening than they otherwise would. Their medical team may consider using breast MRIs in addition to mammograms for follow-up screening.

Some women with a BRCA mutation decide to have risk-reducing surgery, such as a mastectomy, to lower their risk of breast cancer. Knowing that having this mutation also means a higher risk of ovarian cancer, some decide to undergo surgery to remove their ovaries and fallopian tubes.

If we find someone has an inherited risk, we can use the genetic testing results to narrow down the search for the same mutations in the DNA of other family members.

Its somewhat like locating a persons home. Once you have the address, you can find that person much easier.

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What Is The Name Of The Cancer That Is Caused By Dna Damage

Cancers that result from DNA damage that is passed on are called hereditary cancers. These cancers tend to run in families. They cause hereditary cancer syndromes. But only about 5% to 10% of all breast cancers are hereditary. If you may be at risk for a hereditary cancer syndrome, genetic testing can be helpful.

What Are The Genes That Protect You From Cancer

The breast cancer 1 and breast cancer 2 genes are the genes most commonly affected in hereditary breast and ovarian cancer. Normally, the BRCA1 and BRCA2 genes protect you from getting certain cancers. But certain mutations in the BRCA1 and BRCA2 genes prevent them from working properly, so that if you inherit one

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Should All Breast Cancer Patients Have Genetic Testing

Women who have already been diagnosed with breast cancer: Most doctors agree that not all women with breast cancer need genetic counseling and testing. But counseling and testing is more likely to be helpful if: You were diagnosed with breast cancer at a younger age. You have triple-negative breast cancer.

Breast Cancer Gene Expression Tests

How Do Single

Gene expression tests are a form of personalized medicine – a way to learn more about your cancer and tailor your treatment.

These tests are done on breast cancer cells after surgery or biopsy to look at the patterns of a number of different genes. This process or test is sometimes called gene expression profiling.

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Where To Go For Genetic Counseling And Testing

Most health insurance companies cover testing when its considered medically necessary or medically reasonable, based on the guidelines. Some physicians order genetic testing for their patients with or without a referral to genetic counseling. It varies by physician and institution. Ask your doctor about the possibility of getting a referral to a genetic counselor for an in-depth risk assessment and to explore the option of genetic testing.

If your physician is unable to refer you to a genetic counselor, you can search for a certified genetic counselor on the Finding a Certified Genetic Counselor page of the American Board of Genetic Counseling website.

Direct-to-consumer genetic tests are also available. Some of the major testing laboratories currently charge about $250 for those choosing to self-pay. But be sure to research this option thoroughly to clearly understand what you should expect from this kind of testing. Direct-to-consumer genetic tests typically dont evaluate inherited cancer risk as thoroughly as a test ordered by a medical provider, and results often need to be confirmed at a second laboratory.

CTCA is a cancer center where we only treat cancer. Our oncologists and multidisciplinary cancer experts are familiar with genetic testing and its implications in all stages of cancer and its treatment. We offer genetic counseling to our patients who are referred for genetic testing, and were often able to meet with them quickly.

What Is A Strong Family History

Associate Professor Kirk said a strong family history is when there are three or more affected family members on one side of the family. However sometimes an individual will not know this information, or their family is predominately male. Associate Professor Kirk said in these instances, there are other factors that come into play.

There are other things that we might look for, and they would include: early age at breast cancer diagnosis, the presence of triple negative breast cancer in a young woman, less than 50 years of age at diagnosis, ovarian cancer specifically high grade, invasive epithelial ovarian cancer. Most women with that type of cancer is now offered a genetic test, she said.

Associate Professor Kirk said it is standard practice to first test the genetics of a family member who has been affected by breast cancer and then subsequently decide if it is worth testing other family members.

You can still choose to be tested if your immediate affected family member has died or is not in a position to be tested.

However, Associate Professor Kirk said the information gained from the test can only be used in individual instances and cannot tell the story for the whole family.

The thing is if you find nothing in that women, thats quite reassuring but you still dont know whether there is a genetic fault in the family.

Associate Professor Kirk said it is also a misconception that inherited genetic mutations are more common on the mothers side of the family.

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How Is Hboc Inherited

Normally, each person has 2 copies of each gene in their bodys cells: 1 copy is inherited from a persons mother and 1 copy is inherited from a persons father. HBOC follows an autosomal dominant inheritance pattern. This means that a mutation needs to happen in only 1 copy of the gene for the person to have an increased risk of getting that disease. This means that a parent with a gene mutation may pass along a copy of their normal gene or a copy of the gene with the mutation. Therefore, a child who has a parent with a mutation has a 50% chance of inheriting that mutation. A sibling or parent of a person who has a mutation also has a 50% chance of having inherited the same mutation. However, if the parents test negative for the mutation , the risk to the siblings significantly decreases but their risk may still be higher than an average risk.

Questions To Ask The Health Care Team

Genetic Testing for Breast Cancer

If you are concerned about your risk of cancer, talk with your health care team. It can be helpful to bring someone along to your appointments to take notes. Consider asking your health care team the following questions:

  • What is my risk of developing breast cancer and ovarian cancer?

  • What is my risk for other types of cancer?

  • What can I do to reduce my risk of cancer?

  • What are my options for cancer screening?

If you are concerned about your family history and think your family may have HBOC, consider asking the following questions:

  • Does my family history increase my risk of breast cancer, ovarian cancer, or other types of cancer?

  • Should I meet with a genetic counselor?

  • Should I consider genetic testing?

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Pros And Cons Of Genetic Testing

Its important to consider the advantages and drawbacks of learning whether youve inherited an abnormal gene mutation linked with breast cancer or ovarian cancer.

If one of your family members has a confirmed abnormal BRCA1 or BRCA2 gene and your test result is negative, your genetic counselor can tell you with greater certainty that you have the same relatively low risk of developing breast or ovarian cancer as people in the general population. Routine screening for breast cancer are still important for you, just as it is for everyone. There are currently no widely accepted ovarian cancer screening guidelines for women at average risk of developing the disease. Men with a negative test result have the same extremely low risk of being diagnosed with male breast cancer as men in the general population and the same relatively low risk of being diagnosed with prostate cancer.

If your test result is positive, there are steps you can take to lower breast or ovarian cancer risk, or to detect these cancers early if they develop:

While there are steps you can take to lower breast cancer risk if your genetic test results are positive, there are some limitations to keep in mind:

Evaluation Of Suspected Hereditary Predisposition To Breast Cancer

Individuals with a family and personal history suspicious for a familial syndrome should be referred to a genetic counselor for a comprehensive evaluation. Testing for mutations in cancer-associated genes is individually based, and requires a high index of suspicion for a particular gene based on the clinical situation. In general, when a family history is suggestive, it is best to test the individual with a cancer diagnosis, as this increases the probability of a positive test result. Standard clinical BRCA1 and BRCA2 testing has been carried out using PCR amplification and Sanger sequencing. For the Ashkenazi Jewish population, testing can be initially targeted to the three major founder mutations. In 2007, testing for large rearrangements was added for secondary analysis after research studies published that 6%18% of individuals who are BRCA mutation negative by sequencing can be explained by large insertions and deletions in the BRCA1 and BRCA2 genes using multiplex ligation-dependent probe amplification technology . If a mutation is identified, targeted testing can be done for other members of the family to assess risk. Possible outcomes of genetic testing are a true positive, a true negative , uninformative , or a variant of unknown significance . By definition, a VUS is a detected genetic change without a good description of any correlating clinical risk.

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