Breast cancer in families

Hereditary means being passed on from parents to children.

If 1 or more of your close family members, such as your parent, sibling or child has been diagnosed with breast cancer, you may have concerns about your own risk.

If you’ve been diagnosed with breast cancer, you may worry about what this means for other members of your family.

Most breast cancers are not inherited

Breast cancer is the most common cancer in women in the UK.

However, most breast cancers are not inherited and only a small number of people have an increased risk of developing breast cancer because they have a significant family history.

If you have a relative with breast cancer, it doesn’t necessarily mean you’re more likely to develop it yourself.

Some people have a significant family history of breast cancer

Sometimes, someone’s family history suggests they could be at increased risk of developing breast cancer.

This is known as having a significant family history.

You’re more likely to have a significant family history if, for example, 2 or more of your close family members have been diagnosed with breast cancer. Or if 1 family member has had breast cancer in both breasts.

You may have a significant family history because there’s an altered gene in your family that increases the risk of breast cancer. 

Only about 5 to 10% of breast cancers are due to inheriting an altered gene.

What to do if you’re concerned

If you’re worried about your family history, the first step is to talk to a healthcare professional. 

If you have not had breast cancer yourself, you can talk to your GP.

If you have been diagnosed with breast cancer, you can speak to a member of your treatment team.

Speaking to your GP

Your GP will ask you about your family history. It’s helpful if you can find out as much information as possible before this discussion. 

Your GP will want to know about:

• Family members who have had breast cancer 
• Family members who have had breast cancer in both breasts (bilateral)
• Family members who have had ovarian cancer or multiple types of cancer
• The age of your relatives when they were diagnosed with cancer
• Male relatives who have had breast cancer or prostate cancer
• Jewish ancestry

This includes family members on both your mother’s and father’s side of the family.

Referral for further assessment

If the information suggests you may have a significant family history, your GP can refer you for a family history risk assessment.

GPs follow national guidance when deciding whether to refer you for further assessment.

Your GP may refer you to a specialist family history clinic or regional genetics centre, depending on where you live.

These are specialist services that can assess your individual risk of developing breast cancer.

Being referred for an assessment does not necessarily mean you’re at an increased risk.

Find out more about the family history risk assessment process, including who should be referred.

If you’ve had breast cancer

If you’ve had breast cancer and are worried about your family history or whether your cancer may be hereditary, you can speak to a member of your treatment team.

If appropriate, they can refer you to a specialist family history clinic or regional genetics centre for further assessment. You may also be able to have genetic testing at the breast clinic.

Only a small number of breast cancers are due to having a significant family history. Regardless of your family history, it’s important to be breast aware.

This means:

1. Knowing the signs and symptoms of breast cancer
2. Checking your breasts regularly, so you know what looks and feels normal for you 
3. Contacting your GP if you notice a breast change that’s new or unusual

You might also find it helpful to learn about breast cancer causes and risk factors, and ways you can reduce your risk.