Information on this page is about changed genes which can run in families (genetic). Another word for this is inherited.
For example, a person may have an inherited faulty or changed gene.
Notes on wording:
Breast cancer can affect anybody, and everybody is welcome in CoppaFeel!’s community. We’re actively inclusive in our language and we ask people how they want to be described.
The word ‘chest’ is inclusive of all bodies and genders. When we need to be clinically accurate we use the word ‘breast’. You might prefer to call your chest something else, and that’s ok!
A person with a changed gene is called a carrier. Being a carrier does not mean that you will develop breast cancer, but it does put you at a higher risk compared to the general population.
Something is wrong, for example a faulty gene does not work in the right way.
Genes are a part of each cell in the body and are passed on from parents to children. They are the code for who we are. For example, your eye colour is based on your genes.
Relating to genes. For example, genetic testing can show whether there is a change in a gene.
A genetic counsellor is a specialist who can help you to understand a genetic condition that runs in your family and options for genetic testing.
Changes in certain genes passed on in families can increase a person’s risk of breast cancer. It is important to know that breast cancer is common. Most cases of breast cancer happen by chance or due to lifestyle and environmental factors rather than genetics. Researchers think that only around 5 to 10 out of 100 breast cancers (5 to 10%) are caused by a changed gene.
Source: Cancer Research UK
For women and people assigned female at birth in the general population, there is a 15% lifetime chance of developing breast cancer.
Source: Breast Cancer Now.
An inherited faulty gene is also called a changed gene. We all have genes that protect us against cancer.
A changed gene means one of those genes has a spelling mistake, or a fault. The fault means it can’t repair DNA damage caused by cancer, and the cancer can grow.
Having a changed gene does not mean you have breast cancer. It does mean your risk of getting breast cancer is higher than most other people.
BRCA is a short way of saying BReast CAncer. We all have the BRCA genes, but some people have a change or fault which can increase their risk of breast cancer and other cancers.
Having a change in a BRCA gene does not mean someone will develop breast cancer. It does mean their chance of having breast cancer is higher.
You can read about other changed genes linked to breast cancer here
Usually BRCA1 and BRCA2 genes protect against breast and ovarian cancer. A person may be born with changes in these genes. These changes are passed on in families (genetics). It’s also called:
These all mean the same thing. The person has a higher risk of breast cancer because there is a change in a BRCA gene that reduces its ability to repair DNA damage.
You can read more about the BRCA gene here.
Women or people assigned female at birth with a changed BRCA1 gene have a:
Men or people assigned male at birth with a changed BRCA1 gene have a 0.1% to 1% risk of breast cancer.
Women or people assigned female at birth with a changed BRCA2 gene have a:
Men or people assigned male at birth with a changed BRCA2 gene have a 5% to 10% risk of breast cancer, and up to 25% risk of prostate cancer.
Source: Breast Cancer Now.
Scientists are studying genes linked to breast cancer all the time. This will help genetic specialists understand how these genes work. It will also help them make decisions about genetic testing and breast cancer screening for people at higher risk of breast cancer.
Fole tested positive for the BRCA 2 gene mutation at 24 years-old after 18 months of genetic testing. Knowing her risk of a breast cancer diagnosis was high, she chose to undergo risk-reducing surgery which has given her the freedom to live her life to the fullest.
Members of a family may have the same type of cancer. For example, a family history of breast cancer. When we talk about a family history of cancer, we focus on blood relatives (family members), and it does not mean everyone in the family will have cancer.
It’s important to think about family members on both the mother’s and father’s side of the family.
Both mothers and fathers can carry and pass on a changed gene that increases the risk of breast cancer. While a man (someone assigned male at birth) with a changed gene is less likely to develop breast cancer, he can pass the changed gene on to his children.
Having a parent, sibling or child (first degree family member) diagnosed with breast cancer approximately doubles your risk of breast cancer. This could be a family member of any gender.
This risk is higher when more close family members have breast cancer, or if a family member has breast cancer under the age of 50.
But most people who have a close family member with breast cancer will never develop it.
There are guidelines in the UK to help GPs work out who might have an increased risk of breast cancer due to their family history. Read more here.
Having Jewish ancestry increases your risk of having a BRCA gene change.
1 in 40 Ashkenazi Jews and around 1 in 140 Sephardi Jews has a changed BRCA gene, compared to around 1 in 250 individuals in the UK general population.
The NHS is offering free BRCA gene testing for anyone living in England, aged 18 or over with one or more Jewish grandparent until 31st October 2025.
For more information visit https://jewishbrca.org/
Jnetics is a registered charity dedicated to improving the prevention and diagnosis of Jewish genetic disorders in the UK. Visit their website here: https://www.jnetics.org/
Chai Cancer Care provides free, professional and expert support to any member of the Jewish community affected by cancer, as well as their family and friends. Visit their website here: https://chaicancercare.org/
Women or people assigned female at birth with a changed ATM gene have a moderate risk of developing breast cancer. Moderate risk is higher than the general population. However, it’s still more likely they will not get breast cancer.
A change in the CHEK2 gene can increase your risk of developing breast cancer. People with a CHEK2 change have a 25 to 30 in 100 (25% to 30%) chance of developing breast cancer in their lifetime.
The CHEK2 gene change can also increase your risk of developing other cancers including:
– prostate cancer
– kidney cancer
– thyroid cancer
– large bowel (colon) cancer
Changes in the PALB2 gene increase the risk of developing cancer of the breast, pancreas and ovary. Almost 45 in every 100 women or people assigned female at birth (almost 45%) with a changed PALB2 gene will develop breast cancer by the age of 80.
Peutz Jehers syndrome (PJS) is caused by a change in the STK11 gene. Some signs of PJS can start in childhood. The signs include darker skin around the mouth, lips, fingers and toes. Some people also have freckling around and inside the mouth.
People with PJS have an increased risk of developing:
– breast cancer
– bowel cancer
– pancreatic cancer
– stomach cancer
– ovarian cancer
This syndrome includes Cowden syndrome. It is caused by a change in the PTEN gene. This syndrome increases your risk of developing benign (not cancer) tumours and different types of cancers. This includes:
– breast cancer
– thyroid cancer
– womb cancer
– bowel cancer
– kidney cancer
– melanoma skin cancer
Women or people assigned female at birth with a changed TP53 gene have an up to 85% risk of breast cancer. The lifetime risk for a person with a changed TP53 gene to develop any type of cancer is 90%.
Source: Cancer Research UK
Laura tested positive for the PALB2 gene change after being diagnosed with breast cancer when she was 29. Despite now living with secondary breast cancer, she feels empowered to help others, and is relieved to understand why she developed cancer.
Some genetic conditions caused by rare changed genes are also linked to breast cancer. We have talked about Peutz-Jegher syndrome and PTEN Hamartoma tumour syndrome above.
Read more about these genetic conditions on this Cancer Research UK page
Key words:
First degree relative
Relatives (family members) that share 50% of their DNA. For example a parent and child, or full siblings.
Second degree relative
Relatives (family members) that share 25% of their DNA. For example a grandparent and grandchild, half siblings, aunt, uncle,niece and nephew.
Source: NHS England Genomics Education Programme
Your GP may refer you to a specialist breast clinic or genetics clinic for tests if you have any of the following:
Your GP may also refer you if you have one first degree or second degree relative diagnosed with breast cancer when they were older than 40 years and one of the following:
If you are worried about a history of breast cancer in your family, talk to your GP. You may be asked to write a list of family members who have had any cancer, the type of cancer they had and the age they were diagnosed. This can help GPs to see whether you meet the guidelines for a referral to a genetics specialist.
If your GP thinks you could have a changed gene, they may suggest you are offered genetic testing. The genetic test usually has 2 steps:
If family members who have had cancer are not available, you may be offered genetic testing if you have at least a 10% chance of having the gene change. This usually means you have a strong history of breast cancer at younger ages in your family.
The genetics specialists can work out your risk of getting breast cancer, and may suggest extra screening. You might start having screening from a younger age. Some people decide to have surgery to reduce their risk. You can talk about all of the different options with a genetic counsellor. They will support you to make decisions that are right for you.
If specialists have told you there is a moderate or high risk of developing breast cancer, you may be offered regular screening or surveillance, depending on your age. Surveillance means doctors check you more often than usual, to check for any changes.
Screening aims to find breast cancer early, often before any symptoms appear. Early detection increases the chances of successful treatment.
The type of screening offered will depend on:
For younger people, mammograms may not be offered due to dense breast tissue, which can make the images less clear. In these cases, MRI screenings may be offered. MRI and mammograms may be used depending on the specific risk and breast density.
If you would like to look into this further, your GP can refer you to the nearest genetics team for a CanRisk report. They will talk about your risk of breast cancer. If you are told you have a higher risk of breast cancer, specialists will talk to you about screening and referrals to local NHS breast screening programmes.
In most cases, the risks of screening women under 50 would outweigh the benefits. Women with a high risk of breast cancer can be screened at any age. However, low-risk women under 50 are not invited to be screened as part of the national screening programme. This is because x-rays expose you to a small amount of radiation. Any exposure to radiation can very slightly increase your risk of cancer.
Read more about breast screening on our page here
You can reduce your risk by not smoking and limiting alcohol. Live a healthy, active lifestyle and eat a balanced diet.
Any amount of physical activity is good for you, and is better than none. The more you do, the better!
Most cancers happen due to environment, lifestyle factors, and random chance. When someone carries a gene chance which increases their risk of cancer, this increases their chance of developing cancer in their lifetime but is not a guarantee.
For that reason, identical twins who carry the same genetic change that increases their cancer risk may not both develop cancer. Also, not all twins are identical – non-identical twins share the same genetic make up as siblings born separately, so it is possible for one twin to be a carrier and the other not.
Risk reducing surgery is an operation to remove healthy breast tissue from both breasts. It is also called a risk-reducing bilateral mastectomy.
Although most of the breast tissue is removed, it is not possible to remove it all. There is still a small risk of breast cancer developing.
This operation is only suitable for people who have a high risk of getting breast cancer. The specialists and surgeons will talk to the person about their options for reducing their risk.
If you are in contact with your family, it can be helpful to ask them about previous cancers in blood relatives to learn your family history. The next step would be a GP appointment to talk about your family history. If you cannot find out this information, genetic specialists may not be able to give you a complete risk assessment. They will talk about this with you in more detail.
This depends on your individual clinical pathway. If you have had breast cancer yourself, your oncology team (cancer team) may be able to do a breast cancer risk assessment for you. A risk assessment may also be provided by a clinical genetics service if you have been referred to them by a GP. Breast cancer risk assessment is often done using a tool called CanRisk.
Remember:
Most breast cancers happen by chance. Researchers think that only around 5 to 10 out of 100 breast cancers (5 to 10%) are caused by a changed gene
We updated this information in May 2025. We will look at it again in April 2027.
