If you or a close relative have been diagnosed with breast cancer, it is normal to worry about whether there is an increased risk in your family.
We answer some common questions about breast cancer in families.
Are family members automatically at risk?
As breast cancer is the most common cancer in the UK it is not unusual to have someone in your family diagnosed with breast cancer. Most breast cancers happen by chance and are not inherited, so if you or a relative have been diagnosed it doesn’t automatically increase the risk for other family members.
However, a small number of people have an increased risk because they have a ‘significant family history’.
What is a ‘significant family history’?
You may be considered to have a significant family history if:
- you or a close relative has had breast cancer before the age of 40
- you or a close relative has had breast cancer in both breasts (bilateral breast cancer)
- you have had breast cancer known as triple negative (in particular if you were diagnosed under the age of 50)
- you and a close relative have had breast cancer
- two or more close relatives have had breast cancer
- you have close relatives who have had breast cancer and others who have had ovarian cancer
- a male relative has had breast cancer.
Other factors such as being of Ashkenazi Jewish ancestry, or having other rare cancers or genetic conditions in the family can also increase the risk. Find out more on our family history web pages.
Having a significant family history puts you at increased risk of developing breast cancer. Blood relatives will also be at increased risk. If you’ve already had breast cancer, a significant family history may further increase your risk of developing a new primary breast cancer.
What should I do if I’m concerned?
Risk can be managed, so if you’re concerned it’s important to find out your level of risk.
The first step is to talk to your GP (local doctor), or if you have been diagnosed with breast cancer yourself, speak to your specialist breast care team. They may refer you for a family history risk assessment.
If you are found to be at high risk, you may also be offered genetic testing to find out if you have inherited an altered gene.
What are ‘breast cancer genes’?
If you have a significant family history, it may be because an altered gene that increases the risk of breast cancer runs in your family. Around 5% of breast cancers are due to inheriting an altered gene.
If you have inherited an altered gene, your chance of developing breast cancer (and possibly other cancers) is far greater than the general population. The most commonly inherited altered genes are called BRCA1 and BRCA2.
Talk to other people who are worried about or are living with an increased risk through the 'Genes and breast cancer' section of our online Forum.
If you want to talk through your concerns with one of our experts, call us free on 0808 800 600.