Breast cancer in families

If one of your close family members, such as your mother, father, sister or daughter, has been diagnosed with breast cancer, you may have concerns about your own chances of developing breast cancer.

If you’ve been diagnosed with breast cancer yourself, 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.

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.

This may be because there’s an altered gene in their family that increases the risk of breast cancer. 

Only about 5–10% of breast cancers are due to having inherited an altered gene.

Someone may be more likely to have a significant family history if two or more close relatives were diagnosed with breast cancer at a younger age, or if one relative has had breast cancer in both breasts.

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. 

Who you should talk to first will depend on your situation.

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.

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.

Referral 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 have had breast cancer

If you have had breast cancer yourself and are worried about your family history or that 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 feel reassured to know that only a small number of breast cancers are due to having a significant family history.

However, breast cancer is still the most common cancer in women in the UK.

1 in 7 women in the UK will develop breast cancer in their lifetime.

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

It’s also useful to know about breast cancer causes and risk factors, and how you might be able to reduce your risk of breast cancer.