Family history of cancer and genetic testing

What does having a family history mean?

Cancer is common – many people have someone in their family who has (or had) cancer. Many people worry about what it might mean for their own health if there are people in their family who have developed cancer.

If you have a family history of cancer it can mean

  • Cancer has developed by chance in your family (most common)
  • You may have an increased risk of getting cancer
  • You may have an inherited faulty gene causing an increased chance of cancer. It is important to know this is only a very small percentage of certain cancers (up to 5%).

What cancers increase my risk of getting cancer?

People with a family history of the following cancers may be at a moderately increased risk of developing these cancers. This does not mean it is an inherited cause. Talk to your doctor about what you can do to reduce your risk. You may need to be tested or discuss some lifestyle changes.

What type of cancers are due to an inherited faulty gene?

It is thought that up to 5% of the following cancers may involve an inherited gene.

  • Bowel cancer
  • Ovarian cancer
  • Melanoma
  • Breast Cancer

Genetic testing

Genetic testing aims to detect faulty genes that may increase the risk of developing certain cancers. For example, BRCA1 and BRCA2 genes are now known to be linked to the development of hereditary breast and ovarian cancer.

Testing is available to families with a high risk of having inherited a faulty gene, based on a strong history of cancer in the family.

A family member who already has a specific cancer, is tested first to identify the faulty gene. If the faulty gene causing the cancer is found, testing may be offered to other family members who have no signs of cancer.

Testing involves taking blood and is carried out by specialist laboratories.

What should I do if I am worried about having an inherited faulty gene?

Find out what types of cancer have occurred in your family and the age each person was when they got cancer. It is important to record the family members not affected by cancer. Talk to your doctor who can help you find out if your family history is of concern. If necessary your doctor may refer you to a family cancer clinic or genetic counselling service.

If you have any concerns call Cancer Council on 13 11 20.

Click here for a list of Cancer Genetics Counselling Services