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Genetic Test For Breast Cancer

Genetic Testing For Hereditary Breast And Ovarian Cancer

Genetic Testing for Breast Cancer

Genetic testing is available for hereditary breast and ovarian cancer. Most breast and ovarian cancer is not caused by inherited mutations, so genetic testing will not help most women with a family health history of breast and ovarian cancer. Genetic testing will not identify the cause for some hereditary breast and ovarian cancers, because the genes affected in these cancers are not yet known.

Genetic counseling before genetic testing for hereditary breast and ovarian cancer is important to determine whether you and your family are likely enough to have a mutation that it is worth getting tested. Usually, genetic testing is recommended if you have:

  • A strong family health history of breast and ovarian cancer
  • A moderate family health history of breast and ovarian cancer and are of Ashkenazi Jewish or Eastern European ancestry
  • A personal history of breast cancer and meet certain criteria
  • A personal history of ovarian, fallopian tube, or primary peritoneal cancer
  • A known BRCA1, BRCA2, or other inherited mutation in your family

The BRCA1 and BRCA2 genes

Genetic counseling after genetic testing is important to help you understand your test results and decide the next steps for you and your family:

  • What it means for your family:
  • If other family members decide to get genetic testing, their test should check for the same mutation you have.
  • Your parents, children, sisters, and brothers each have a 1 in 2 chance of having the same mutation.
  • What it means for you:
  • How Accurate Is Genetic Testing For Breast Cancer

    Generally speaking, genetic testing is quite accurate at detecting known genetic variants. But these tests cannot tell you whether youll eventually develop breast cancer.

    Receiving a positive result means that, compared to the general population, youre at an increased risk of developing breast cancer. Different gene variations can be linked to different levels of risk.

    A positive result doesnt mean that youre certain to get breast cancer in the future. In fact, its possible youll never develop breast cancer. Your genetic counselor can give you a better idea of your breast cancer risk.

    Similarly, a negative result doesnt mean that youll never develop breast cancer.

    Tests dont always cover a broad range of gene variations. Its possible that you may have a harmful variation that wasnt covered by your test.

    Mutations That Increase Breast Cancer Risk

    The majority of breast cancer patients are the only member of their family with breast cancer and most cases are attributed to environmental or lifestyle factors. Fewer than 15% of women with breast cancer have a first-degree relative with this disease,1 and only a small fraction of the population carries inherited germline mutations that increase their lifetime cancer risk. Several genes associated with an increased risk of breast cancer have been identified. The level of increased risk and type of cancers that occur in a family will vary with the particular gene involved. Mutations in each gene are rare, however collectively these mutations account for a significant amount of hereditary cancer susceptibility in the population.

    Read Also: What Are The 3 Types Of Breast Cancer

    Considering Genetic Counseling And Testing For Breast Cancer Risk

    If you’re concerned about your risk because of a personal or family history of breast cancer, talk with your doctor. As a first step, your doctor might use one of several risk assessment tools that are now available. These mathematical models use your family history and other factors to help give you and your doctor a better idea about your risk of having an inherited BRCA gene mutation. But these assessment tools aren’t perfect, and each one might give different results, so doctors are still trying to figure out how best to use them.

    Regardless of whether one of these tools is used, your doctor might suggest you could benefit from speaking with a genetic counselor or other health professional who is trained in genetic counseling. They can review your family history in detail to see how likely it is that you have a family cancer syndrome such as HBOC. The counselor can also describe genetic testing to you and explain what the tests might be able to tell you, which can help you decide if genetic testing is right for you.

    Genetic testing is covered by many health insurance plans, but it might not be covered by some of them.

    If you do decide to get tested, the genetic counselor can also help explain what the results mean, both for you and possibly other family members. To learn more about genetic testing in general, see Genetics and Cancer.

    Criteria For Brca Testing

    Genetic Testing In Cancer

    The current USPSTF guidelines state that the target population for BRCA testing includes high risk individuals who have a personal or family history of breast or ovarian cancers at a young age , that suggests inherited cancer susceptibility, when an individual has access to a health professional who is trained to provide genetic counseling and interpret test results, and when test results will aid in decision making.32 Recommendations vary, but the following criteria are generally considered when evaluating patients for genetic testing: 1) breast, colorectal, or endometrial cancer diagnosed before age 50, 2) bilateral breast cancer, 3) two primary breast cancers or clustering of breast and ovarian cancer, 4) multiple cancers at a young age, 5) rare cancer presentation at any age, 6) two or more primary types of BRCA1- or BRCA2-related cancers in a single family member, or 7) family history of male breast cancer.

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    Breast Cancer Gene Testing Kits

    The first FDA-approved breast cancer gene test, the Personal Genome Service Genetic Health Risk Report for BRCA1/BRCA2 , was approved by the U.S. Food and Drug Administration in 2018. The test kit is supplied by 23andMe, a company that is popular for producing reports that identify a persons ancestry and countries of origin.

    This at-home test can identify three different BRCA1 and BRCA2 genetic mutations that tend to be associated with breast cancer among people of Ashkenazi Jewish descent. According to reports, Ashkenazi females who test positive for these genetic abnormalities may have a 50 to 75% percent chance of developing breast cancer, which is significantly higher than the risk for females who do not have the mutations. These mutations rarely occur in other ethnic populations.

    At-home genetic tests are available through other companies, and you can have genetic tests for other diseases besides breast cancer. While other test kits may provide valuable information, it is hard for a consumer to know for sure. Because test kits that are not federally approved have not gone through the rigorous FDA approval process, it is unclear whether they work. And, because they are not regulated by the FDA, you may not have access to their data and track records.

    Brca1 And Brca2 Genetic Testing Or Expanded Panel Testing

    In most cases, the first person tested is the family member with breast cancer .

    • If no mutation is found, the cancer was unlikely due to a BRCA1/2 or other inherited gene mutation included in the test.
    • If a gene mutation is found, other family members may have the same gene mutation. If thats the case, they should consider targeted gene testing for the specific gene mutation or expanded panel testing that includes the mutation.

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    The Future Of Genetic Testing

    Genetic testing is certainly becoming more accepted but there is still a long way to go,” Nussbaum says. The problem is that guidelines are not updated as quickly as is our understanding of gene-disease relationships in this fast-moving field and they havent kept pace with the changes in cost and availability.

    In 2019, the American Society of Breast Surgeons released an official statement recommending that all breast cancer patients and their family members be offered genetic testing.

    Nussbaum says that providers have been slow to follow the ASBS lead, but he is hopeful that “with the strong and growing evidence of the benefits of universal testing well see guidelines begin to change and come to reflect what Mayo Clinic is making standard practice genetic testing for all cancer patients.

    Harms Of Genetic Counseling Genetic Testing And Interventions

    A New Genetic Test for Women at Risk for Breast Cancer

    The USPSTF reviewed the psychological effects of test results. Nine studies evaluated breast cancer worry or distress after genetic testing. Increased worry was found in 7 studies,77,106-111 particularly in women who are BRCA1/2 mutation carriers, and 2 studies reported decreased worry.112,113 Studies reporting anxiety related to genetic testing were mixed, with 4 reporting increased anxiety,106,109,113,114 2 reporting decreased anxiety,111,115 and 6 reporting no association.75,108,112,116-118 Two studies noted higher anxiety in women who were not tested compared with those who were tested.111,119 Of the 8 studies evaluating depression, none reported increases in anxiety after genetic testing.75,108,111,112,115,117,118,120

    Eight placebo-controlled trials and 1 head-to-head trial of tamoxifen and raloxifene reported harms of risk-reducing medications. Raloxifene and tamoxifen increased risk for thromboembolic events compared with placebo, and raloxifene caused fewer events than tamoxifen in the head-to-head trial.78,126,127 An increased risk of endometrial cancer was seen with tamoxifen but not with raloxifene or aromatase inhibitors. Women using tamoxifen had more cataract procedures compared with placebo or raloxifene.79,90 The most common adverse effects were vasomotor symptoms and vaginal discharge, itching, or dryness for tamoxifen and vasomotor symptoms and leg cramps for raloxifene.28

    Recommended Reading: How To Self Screen For Breast Cancer

    Response To Public Comment

    A draft version of this Recommendation Statement was posted for public comment on the USPSTF website from February 19 through March 18, 2019. In response to public comments, the USPSTF clarified language regarding risk assessment and included additional information on the risk assessment tools referenced in the recommendation. It also incorporated language clarifying that the recommendation includes women with a personal history of BRCA-related cancer who have completed treatment and are considered cured.

    Comments requested that the population under consideration be expanded to include other BRCA-associated cancers such as pancreatic cancer, melanoma, and prostate cancer, as well as men with breast or prostate cancer. The USPSTF recognizes the association of BRCA1/2 mutations with cancers such as pancreatic, prostate, and melanoma. However, the scope of the recommendation is limited to the prevention of breast, ovarian, tubal, and peritoneal cancer because the net benefit demonstrated was in the prevention of these cancers. The USPSTF did not review evidence on the benefits or harms of risk assessment, genetic counseling, and genetic testing in men.

    Funding/Support: The USPSTF is an independent, voluntary body. The US Congress mandates that the Agency for Healthcare Research and Quality support the operations of the USPSTF.

    Other Cancer Risks For People With Hboc

    Anyone with mutations in the BRCA2 gene may be at an increased risk of other types of cancer, including melanoma and pancreatic, stomach, esophageal, and bile duct cancers.Mutations in other genes may be associated with an increased risk of developing breast and other cancers, including the Li-Fraumeni syndrome , Cowden syndrome, and others. The pattern of cancers in the family is often a clue to the specific gene that may explain the hereditary cancer for that family. Multigene panels are available for people with a strong personal and family history of cancer. Multigene panel tests includeBRCA1 and BRCA2 and many other genes that increase the risk of breast, ovarian, and other cancers. If your BRCA1 and BRCA2 test was negative, then you may or may not have mutations in other genes. A newer type of testing, called next generation sequencing, massively parallel sequencing, or deep sequencing, has made testing for multiple genes at the same time faster and less expensive. If a genetic mutation is found, this could explain the cancers in a specific family and provide information about who is at risk and the appropriate types of monitoring and prevention/risk reduction methods.

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    What Are The Estimated Cancer Risks Associated With Hboc

    Cancer risks for women with HBOC

    • Lifetime risk of breast cancer 45% to 75%

    • Lifetime risk of ovarian cancer

      • BRCA1 gene mutation 25% to 40%

      • BRCA2 gene mutation 10% to 20%

    • Developing a second breast cancer 20% to 40%

    Cancer risks for men with HBOC

    • Lifetime risk of breast cancer

      • BRCA1 gene mutation 1% to 2%

      • BRCA2 gene mutation 6%

      • BRCA1 gene mutation some increased risk

      • BRCA2 gene mutation 20%

    • Men with a BRCA2 gene mutation have a significantly increased risk of developing more aggressive prostate cancer before age 65 and therefore screening should begin at age 40.

    What Are The Benefits Of Genetic Testing For Cancer

    Is Genetic breast cancer testing of all women worth the cost?

    Genetic testing for cancer can have several potential benefits. These can include:

    • Peace of mind. If a certain type of cancer runs in your family, a negative test result can give you peace of mind that you havent inherited certain variants.
    • Preventative actions. Learning that you have a variant that increases your cancer risk can help you to take preventative steps early and look out for potential cancer symptoms, if they develop.
    • Family testing. Its possible that immediate family members can learn about their cancer risk from your results. It may also encourage them to get tested.

    Also Check: How Can I Tell If I Have Breast Cancer

    Who Can Be Tested For Inherited Faulty Genes

    You may be eligible for an NHS genetic test if cancer runs in your family and you are worried you may get it too. The test can tell you whether you have inherited a faulty gene that increases your risk of cancer.

    Testing for genes that increase the risk of cancer is called predictive genetic testing. A positive result means you have an increased risk of developing cancer. But it doesn’t mean that you have cancer or will definitely develop it.

    You may be eligible for an NHS genetic test if:

    • an inherited faulty gene has already been found in one of your relatives or
    • there is a strong family history of cancer in your family

    You need to be referred for genetic testing by a specialist doctor .

    You can have private genetic testing. But you need to think about this carefully. You can find out more about private genetic testing at the bottom of this page.

    At the genetic clinic, you see a genetic specialist or counsellor. They will:

    • look in detail at your family history
    • work out your risk of developing cancer
    • work out whether you need a genetic test

    Your first appointment might be at the clinic or over the phone. During this meeting, the counsellor will ask you questions about any members of your family who have had cancer. And how old they were when diagnosed.

    Your genetic clinic appointment is your chance to ask questions. If youre not sure what to ask you can look at our questions for your doctor.

    You could print them out and add any other questions that you might have.

    The Most Recent Studies Suggest That Between 55% And 65% Of Women Who Inherit A Brca1 Mutation Will Be Diagnosed With Breast Cancer By Age 70

    The counselor reviews family histories, discusses the testing process, and explains benefits as well as potential personal or emotional risks of learning about a genetic mutation that will increase breast cancer risk. In addition as new findings come along that may relate to you, counselors will recontact you. To find such a counselor, you can check with a nearby medical school. You can also call 1-800-FOR CANCER. The National Association of Genetic Counselors has a directory to help women and men find a genetic counselor near them.

    Testing positive for a genetic mutation does not mean you are destined to get breast cancer. It means you are at increased risk, which provides information you can use to take action. A negative test does not mean that you will not get breast cancer. It only means that you do not have a known genetic mutation that increases breast cancer risk.

    Also Check: Is It Possible For Men To Get Breast Cancer

    What Are My Options If I Have A ‘cancer Gene’

    Women in high-risk categories and those who have the genes linked with breast cancer should consider starting regular breast cancer screening at age 25, or 10 years earlier than the age of the youngest relative with breast cancer at the time of their diagnosis.

    Get to know how your breasts look and feel. If you notice any changes, see your doctor right away. And talk with your doctor about blood tests, pelvic exams, and transvaginal ultrasound to look for ovarian cancer.

    Some women choose to have a preventive mastectomy to lower their chances of breast cancer. Itââ¬â¢s also possible to have your ovaries and fallopian tubes taken out. This doesnââ¬â¢t get rid of all risk, but it does significantly lower it.

    Another approach includes using anti-estrogen drugs:

    • Tamoxifen, useful in premenopausal and post-menopausal women
    • Raloxifene , used to treat osteoporosis useful only in post-menopausal women
    • Exemestane , an aromatase inhibitor useful only in post-menopausal women

    Genetic Testing To Learn About Your Risk Of Breast And Ovarian Cancer: Questions For The Doctor

    23AndMe Receives FDA Approval To Test For Breast Cancer Gene Mutations

    If your family has a history of breast or ovarian cancer, its a good idea to discuss it with your doctor.

    Thats because mutations in genes can run in families. If you were born with mutations in certain genes called BRCA1 and BRCA2 genes youre at higher risk of developing breast and ovarian cancer. You may also be at higher risk of developing other types of cancer.

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