Know Your Risk Tool Further Information

What will the tool tell me?
You will be asked questions about your family history of cancer. When you have finished, you will be provided a summary page that you can print off and take to your doctor.

The answers you provide will help guide advice about your risk of breast and ovarian cancer and your options for getting more information. You may be advised to talk to your doctor e.g. GP (local doctor) or a breast specialist. This may also include seeking a referral to a Familial Cancer Centre (FCC). A referral to an FCC does not mean you are necessarily at high risk of developing breast or ovarian cancer. Nor does it mean that you will be offered or need to have a genetic test.

Understanding hereditary breast and ovarian cancer
Many women who develop breast or ovarian cancer do not have a family history of either cancer. Their cancers are mainly thought to be due to ‘chance events’ (random changes that happen in a breast or an ovarian cell).

For most women who have a family history of breast or ovarian cancer, there is usually only one person with a breast or ovarian cancer. This type of family history does not automatically put the other family members at a high risk for cancer as those cancers are most likely caused by ‘chance events’.

Some cancers are due to changes (mutations) in combinations of unknown genes, which are still being understood by researchers. Some cancers might be due to a mutation in a hereditary gene where genetic testing is now possible.

Looking at a family history is a good starting point to assess why a history of breast and/ovarian cancer might have occurred and what this means for your risk.

The type of cancer makes a difference to the chance of a hereditary cause
About 1 in 20 (5%) of women with breast cancer and about 1 in 7 (15%) of women with ovarian cancer, have an inherited mutation in a known high risk cancer gene. Many women with a mutation will also have a family history of breast and/or ovarian cancer, although some won’t.

Features of a hereditary cause for a family history of breast and/or ovarian cancer
These include:

  • whether a relative is already known to have had a mutation found on a genetic test
  • the number of close relatives who have had breast or ovarian cancer,
  • a relative with certain types of breast or ovarian cancer
  • a relative with cancers occurring at young ages (e.g. before age 40 years for breast or before age 50 for ovarian cancer)
  • relatives with cancer in both breasts
  • male relatives with breast cancer
  • a relative who has had both breast and ovarian cancer
  • an ethnic background from a population where some mutations are more common e.g. Eastern European (Ashkenazi) Jewish ancestry

These are factors we will ask questions about in the Assess Your Risk tool.

Men and women with a personal history of breast or ovarian cancer
The Assess Your Risk questionnaire based tool we have created is not aimed at men or women who have had cancer, because additional details your doctor will have about your cancer is important in your assessment. Talking to your doctor will enable you and your doctors to take into account the type of cancer you have had and your family history. This is important as certain types of breast and ovarian cancer are more likely to have hereditary causes than others.

All men with breast cancer are advised to talk to their doctor about a genetic assessment.

Most types of ovarian cancer are of the kind (called high grade serous cancer) where genetic testing is now offered. This is because for about 1 in 7 (15%) women a genetic cause may be identified. So if you have ovarian cancer at any age, have a conversation with your doctor about whether you should be referred to a Family Cancer Centre.

If you have breast cancer that is ‘triple negative’ (this means where the cancer pathology report shows hormones such as oestrogen or progesterone and another protein called her-2 do not bind to the breast cells) then talk to your doctor about whether a genetic assessment is recommended. This is usually considered if your triple negative cancer was diagnosed before 50 or if you also have a family history of breast or ovarian cancer. There are other situations where a breast cancer diagnosis warrants more discussion with your doctor about whether you should be referred to a Family Cancer Clinic.

National referral guidelines for health professionals on when to refer to genetic services are listed on the website www.eviq.org.au.

Genetic testing
This tool does not assess whether you would be offered a publically funded gene test. For more information about Genetic Testing click here. In general, some family histories are likely to be due to genes that current genetic testing cannot find, so genetic testing is not useful for everyone. What is often still useful is a more detailed assessment of your risk of developing breast and ovarian cancer, along with advice on check-ups and ways to reduce those risks.

In some families it best for your relative with cancer to talk first to their doctor or a Familial Cancer Centre. This is because their information (such as the exact type of cancer they had) can be a useful guide to whether a genetic mutation is likely to be present in your family. This can then help your doctor or an FCC to advise you on your risk of developing breast or ovarian cancer and whether genetic testing might benefit your family. We know that it is not always possible to talk to a relative who has had cancer about these issues and so you may have to talk to your doctor or a Familial Cancer Clinic directly in the first instance.

Other information about the tool
There are national guidelines for referral to a Family Cancer Clinic and guidelines about how to assess women with a family history of cancer. These guidelines have been used to inform the tool and can be viewed at www.eviq.org.au.

Although great care has been taken in developing and testing the tool to check the outputs, no formal validated study has taken place.

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