Patient information
BRCA1 and BRCA2 gene testing
Information sheet for patients with cancer
In most people cancer occurs by chance. In a minority of people with ovarian cancer (about
15%) or breast cancer (about 3%), cancer occurs because they have a mutation (change) in the
BRCA1 or BRCA2 gene. There may also be other genetic causes of breast and ovarian cancer
that have not yet been identified and that we are not able to test for.
BRCA1 and BRCA2 mutations result in increased risks of breast and ovarian cancer. They occur
more frequently in women who have had both breast and ovarian cancer, those with
particular types of breast or ovarian cancer, or if there is a strong family history of breast
and/or ovarian cancer. It can be helpful to identify if a cancer is due to a BRCA1 or BRCA2
mutation because it provides you and your doctors with information that can help treat your
cancer and to reduce your risk of future cancer. It can also provide information for relatives
about their risks of cancer.
Why am I being offered this test?
You are being offered a test to look for mutations in BRCA1 and BRCA2 because of your cancer
diagnosis.
What are the benefits to me?
Knowing whether or not you carry a mutation in BRCA1 or BRCA2 gives the cancer team more
information about your cancer. This can help decisions about the treatments they recommend for
you, for example which chemotherapy drugs or surgery would be most suitable. It will also give
better information about your risk of developing cancer in the future.
What are the possible results of BRCA1/BRCA2 testing and what implications do these results
have for me and my family?
Testing can reveal one of three results:
1) No BRCA1/BRCA2 gene mutations are found- This is the most likely outcome, as most
women with cancer do not have a mutation in BRCA1 or BRCA2. This means that it is very
unlikely that your cancer is caused by a mutation BRCA1 or BRCA2 gene. This would be
quite reassuring for you and other relatives as it would indicate that your cancer was less
likely to be due to hereditary factors that would put them at very high risk of cancer.
However there may be other genes that increase the risk of breast/ovarian cancer that we
have not yet identified so your relatives may still be at a higher risk than the general
population and may qualify for extra screening. No predictive testing will be available for
other relatives unaffected with cancer. Very occasionally mutations in other genes can be
involved in causing breast or ovarian cancer. If your doctors think other genetic factors
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might be involved in your cancer then they may offer you a referral to the genetics clinic to
evaluate this.
2) A cancer-causing gene change (mutation) is found -This confirms that an inherited
tendency to breast/ovarian cancer is present in the family. Women with breast/ovarian
cancer who carry this mutation will have a higher chance of developing a new breast or
ovarian cancer. Your cancer team will use this information to inform the options they offer
you in terms of your treatment and ongoing management. Other members of the family
can have a predictive genetic test to see if they have inherited the same gene alteration.
3) A ‘variant of unknown significance’ (VUS) is found- Very occasionally (<1%) we find a gene
change, known as a ‘variant’. This is gene change of unknown significance may be entirely
harmless. This result means the family still has an increased risk of breast/ovarian cancer
due to the family history. You will be offered a referral to the genetics team to discuss this
further.
Do I have to have the test?
No, having this test is optional. Your decision will not affect the standard of care you receive from
the hospital or doctor, which will be based on the available information. Some women decide that
they do not want testing for the BRCA1 or BRCA2 genes so near to their diagnosis of cancer but
may choose to be tested at a later date when their treatment is complete. You can see the
genetics team to discuss testing at any time in the future; a referral could be made by the breast
cancer treatment team or your GP.
What if I am undecided if I want to have the test?
You could ask to be referred urgently to the Genetics team who would be happy to explore further
with you some of the pros and cons of testing in your particular situation.
What will happen next if I say yes?
If you decide to have the test, you will be asked to sign a consent form. Two blood samples will be
required for the test.
How will I receive the results of the test?
Your cancer treatment team give you the result. The results may take up to 8 weeks. They will
then arrange to discuss these results with you, and if appropriate, you will also be offered a referral
onto the genetics service to discuss the wider implications for you, and testing and screening for
your family.
Will my information be confidential?
All data collected about you will be held under the provisions of the 1998 Data Protection Act and
stored in secure files. The only people who will know your identity are the hospital staff and a few
trained staff reporting the results that are bound by a professional duty to protect your privacy.
If you have any questions please contact ………………………………………
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