Breast cancer in the family

You may be surprised to know that most people who develop breast cancer do not have a close relative with the disease. While people can’t "inherit breast cancer,” a small number of people do inherit a genetic predisposition to the disease.

Approximately 5 per cent of breast cancers occur in people who have inherited a gene abnormality from their mother or father. The most common inherited gene mutations that increase the risk of breast cancer are in the genes BRCA1 and BRCA2. The BRCA1 and BRCA2 genes usually protect us from developing breast cancer.

Inheriting a gene mutation in one of these genes increases the risk of developing cancer. While having a breast cancer gene mutation increases your risk of developing breast cancer, it does not mean that you will definitely get breast cancer.

Abnormalities in BRCA1 or BRCA2 occur in about 1 in 400 (0.2 per cent) Australian people, but they are more common in some ethnic groups – for example they occur in about 1 in 40 (2.5 per cent)  people with Ashkenazi Jewish (Eastern Europe) heritage.

There are also other, even less common, inherited gene abnormalities that increase the risk of developing breast and other cancers.

It’s important to remember that gene abnormalities can also be passed through the father's side of the family, so the family history on that side is just as important as on your mother’s side.

Concerned about your risk?

If you are concerned that your family may be at increased risk of developing breast cancer, it’s a good idea to talk to your GP or breast cancer specialist about it. You can also use the iPrevent breast cancer risk tool to determine the significance of your cancer family history (see Things you can do next). If you are particularly concerned, you can also contact a family cancer clinic.

Family cancer clinics

Attending a Family cancer clinic can help you sort out the relevance of your cancer family history. If it is appropriate for you, they can arrange for you and your family to have genetic testing. This can determine whether you or another family member carries a gene abnormality that increases cancer risk (such as in BRCA1 or BRCA2). You will have access to counselling before and after testing.

Once your cancer risk is assessed, family cancer clinics can also help you draw up a health plan to manage your risk. This may include changing lifestyle factors, regularly monitoring your breasts for any changes (with mammography and sometimes special tests like MRI), taking medication or having surgery. 

Decisions about which options you want to explore are always up to you and family cancer clinicians are very experienced in helping you to make decisions that are right for you as an individual and fit with your personal beliefs and values.

There is no charge for a consultation at a family cancer clinic. Genetic testing is free for people who meet certain family history criteria. Some people who don’t meet the criteria may choose to self-fund a genetic test, which costs several hundred dollars. Family cancer clinics operate through public hospitals and some private hospitals. Your GP can refer you to a clinic in your area, or you can telephone a clinic yourself to make an appointment. 

For more information about family history and cancer, visit the Cancer Council Australia website or phone the Cancer Council Helpline on 13 11 20.