How can I tell if my family has a history of cancer?

Look at the family history on both your father’s and mother’s side of the family. The clues that cancers in the family may be due to an inherited faulty gene include:

Number of blood relatives* who have had cancer:
The more blood relatives who have had cancer (in particular breast, ovarian and/or bowel cancer), the more likely the cancer is due to an inherited faulty gene.

Ages at which cancers in the family developed:
The younger people were when they developed cancer (compared to what is expected in the general community), the more likely it is to be due to inherited factors.

Pattern of cancer in the family:
The type of cancer and who it affects in the family are important. In some families there are a number of blood relatives who develop the same type of cancer, such as breast or bowel cancer. In other families there are some cancers that may run in the family (e.g. breast, ovarian or bowel cancer and cancer of the uterus). This happens because some faulty genes can cause more than one type of cancer.

*A blood relative is someone related by blood (e.g. grandmother, father, sister), not marriage.

The more clues that are present, the more likely it is that there is an inherited faulty gene in the family causing a higher than usual chance of cancer. However, it is not definite. It is important to know that some people who inherit a faulty gene which causes an increased risk of cancer never go on to develop cancer.

What should I do if I have a family history of cancer?

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

Your family history of cancer can change over time, so it is important to keep your doctor updated about any new cancer diagnosed in your family.

More information and resources

For more information about family cancers and genetic counselling services, please contact your doctor or call the Cancer Council Helpline on 13 11 20.