What is genetic testing for hereditary breast and ovarian cancer?

Genetic testing for hereditary breast and ovarian cancer is done through a complex lab test but all that is required from you is a blood sample. The test looks for inherited changes (called mutations) in two genes that everyone is born with: BRCA1 and BRCA2. Scientists have identified specific mutations in these genes that increase your risk of developing breast and ovarian cancer. Not everyone with a mutation in these genes will develop cancer.

Why would I have genetic testing for hereditary breast and ovarian cancer?

There are many reasons why people decide to have genetic testing for hereditary breast and ovarian cancer. Typically, it is because they have a personal and family history of cancer and want to know if they are at risk of developing hereditary cancer. Some people feel that knowing their risk for developing cancer allows them to make informed decisions about health management. It may also allow other family members to do the same.

How do I get tested?

To determine whether you are eligible for genetic testing that would be fully covered under your provincial health insurance, a genetic counsellor will first assess your personal and family medical history. There are specific criteria (which may vary from province to province) that help guide a genetic counsellor’s assessment. Genetic counselling clinics are usually located in hospitals or cancer centres. The clinics offer both genetic counselling and genetic testing by certified health care professionals. There are different ways to get an appointment:

  • Ask your family doctor for a referral
  • Call a clinic yourself. Contact the Canadian Association of Genetic Counsellors to find a clinic near you. Not all clinics see individuals for hereditary breast and ovarian cancer so you would need to ask that when you call.
  • If another family member has been tested, you may contact the same clinic

What if I am of Ashkenazi Jewish heritage?

People of Ashkenazi Jewish heritage (Jewish people descended from Eastern Europe) have a higher chance of having a BRCA1 or BRCA2 gene mutation. Therefore, the criteria for testing are different for this population. If you are of Ashkenazi Jewish heritage and have a first degree relative with breast or ovarian cancer, contact your family doctor for a referral or call your local genetic counselling clinic if would like to discuss testing options.

What should I consider when making a decision about genetic testing?

The decision about whether or not to have genetic testing is a personal one. It is important to make the decision that is right for you, at the right time in your life. You may want to consider some of the advantages and disadvantages of genetic testing:

Advantages 

  • Results can clarify your cancer risk
  • Allows you to make informed decisions about your health
  • Provides helpful medical information for family members
  • Enables other family members to have testing
  • Provides an explanation for your personal or family history of cancer
  • Negative results may reduce anxiety

Disadvantages

  • Results may not clarify your cancer risk
  • Results cannot tell you if you will develop cancer
  • Family members may react negatively to this information
  • Positive results may cause you distress
  • If a mutation is not found, you may feel that you have no chance to get cancer – but everyone has a risk of develop cancer

You may also want to ask yourself these questions:

  • What are the risk management options available to me?
  • If I have the gene mutation, what steps would I consider to lower my risk?
  • What are my reasons for getting tested?
  • How am I prepared to cope with the result?
  • With whom will I share my genetic test results? How will I do this? Will this information impact my relationships?
  • If I have the gene mutation, what steps would I consider to lower my risk?

What are the possible test results?

Genetic testing for BRCA mutations can give many possible results. Here is a review of the different results and what they mean to you and your family:

Click on the drop-down menu below to review results.

1) A BRCA1 or BRCA2 gene mutation is identified (positive result)

You have inherited a mutation in BRCA1 or BRCA2 and have an increased risk of developing breast, ovarian and possibly other types of cancer. A positive genetic test result is not a diagnosis of cancer and cannot predict whether or when cancer will develop. What this result means for you and your family:

  • Provides a genetic explanation for certain cancers in your family.
  • Your first degree relatives (parents, brothers, sisters, and children) have a 50% chance of having this gene mutation.
  • Genetic testing for this specific gene mutation is available to adult family members.
  • You may choose certain treatments to reduce your risk of developing cancer and/or enhanced screening options to help detect cancers sooner.

2) A BRCA1 or BRCA2 gene mutation is not identified AND you are the first person in your family to be tested

You do not have a BRCA1 or BRCA2 mutation that can be identified with the technology currently available. Some genetic counsellors refer to this result as “uninformative.” Possible reasons for this result include:

  • The cancer in your family is less likely to be hereditary.
  • There is a mutation that cannot be detected with current technology, either in BRCA1 or BRCA2.
  • There is a mutation in another gene which has not yet been discovered.
  • There is a mutation in another gene that is currently not being tested for.

What this result means for you and your family:

  • Does not provide a hereditary reason for the cancer in your family at this time.
  • Adult family members with cancer may still be eligible to be tested (your cancer may have happened by chance but there still could be a BRCA gene mutation causing cancer in your family).
  • Your cancer screening recommendations are based your personal and family medical history.
  • Genetic research is ongoing so it is good to call your genetic counsellor every few years to see if any new testing options are available.

3) A BRCA1 or BRCA2 gene mutation is not identified (negative result) but has been identified in at least one other family member

You have not inherited the BRCA1 or BRCA2 mutation identified in your family and do not have an increased risk of developing breast, ovarian, or other associated cancers. What this result means for you and your family:

  • Your risk for breast, ovarian and other cancers associated with hereditary breast and ovarian cancer is the same as the general population.
  • You are encouraged to follow the cancer screening guidelines for the general population.
  • Your children cannot inherit the BRCA1 or BRCA2 gene mutation from you as you cannot pass down what you do not have.
  • Other family members may still have inherited the gene mutation and would still be eligible for genetic testing for the gene mutation identified in your family.

4) Testing reveals a gene mutation of unknown significance

A gene mutation is identified but it is not known if the mutation increases your risk of breast or ovarian cancer. What this result means for you and your family:

  • Researchers are unable to tell whether this specific mutation is the reason for the cancer in your family. Your cancer screening recommendations are based your personal and family medical history.
  • Adult family members are likely not eligible to be tested for the BRCA gene mutation of unknown significance.
  • Adult family members with cancer may still be able to be tested for a BRCA1 or BRCA2 gene mutation (your cancer may have happened by chance but there still could be a known BRCA gene mutation causing cancer in your family).
  •  You should contact your genetic counsellor every few years to see if more information has been gathered about the significance of your mutation or if any new genetic testing options may be available.

How long will it take to get my test results?

The time it takes to get your results can vary significantly and may take up to a year. If you are the first person in your family to be tested, it will generally take longer than if you are being tested for a gene mutation already found in another family member.

How might I feel after receiving my test results?

Every person will have a different experience with genetic testing. However, there are some common feelings that many people experience when they receive their results.

If testing identifies a gene mutation, you may feel angry, anxious, or afraid. However, you may also feel relieved or empowered by this information. You may have trouble making decisions about risk reduction management or telling other family members.

If testing does not identify a gene mutation, you may feel relieved, but you may also feel uncertain or fearful about your cancer risk. These are completely normal reactions.

Your genetic counsellor can help by discussing these feelings with you, provide strategies to help you cope with the information and connect you with other support resources.

Could I face discrimination if my results are positive – for example, in getting insurance coverage?

Genetic discrimination means being treated unfairly based on information about your genetic make-up. There are currently no laws that specifically protect Canadians against genetic discrimination.

If you test positive and are applying for private health or medical insurance you must disclose this fact if you are asked. This means that private insurance companies may deny you coverage or charge you more for coverage if they feel you are at a higher risk of developing cancer. If you are concerned about genetic discrimination affecting your insurance options, you may wish to consider your current and future life insurance needs and make arrangements prior to testing.

Your genetic test results would have no effect on your coverage under any public health care plan offered by your provincial/territorial government.

Should my children be tested?

Genetic testing is not available to children under 18 years of age. Since the cancers associated with hereditary breast and ovarian cancer typically occur in adulthood, test results will not change the health care provided to children. Those being tested should be old enough to decide whether or not genetic testing is right for them, as it can impact their lives on many levels.

Links to more information

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Genetic Testing
FORCE

Genetic Testing for Hereditary Cancer Syndromes
National Cancer Institute

BRCA1 and BRCA2: Cancer Risk and Genetic Testing
National Cancer Institute