In short
Most breast cancer is not inherited — only around 5 to 10% of cases are caused by a faulty gene such as BRCA1 or BRCA2. The biggest risk factors are being a woman and getting older. A healthy weight, regular activity and limiting alcohol lower risk, and those at high inherited risk can be offered extra screening.
It is natural to wonder why breast cancer happens and whether you are at risk. The honest answer is that for most people there is no single cause — it results from a mix of factors, many of them simply down to age and chance. Understanding the main risk factors helps put worry in perspective and shows where you can make a difference.
A common fear is that breast cancer 'runs in the family'. In fact, the great majority of breast cancers are not inherited. But for a minority of families, an inherited gene change does raise the risk significantly — and for them, knowing about it opens the door to extra checks and choices.
What are the main risk factors?
Some risk factors cannot be changed, while others are linked to lifestyle and can be reduced. The most important factors are:
- Being a woman — breast cancer is far more common in women than men
- Getting older — most breast cancers are diagnosed in women over 50
- A significant family history of breast or ovarian cancer
- Inherited gene changes such as BRCA1, BRCA2 or PALB2
- Dense breast tissue
- Being overweight or obese, particularly after the menopause
- Drinking alcohol — risk rises the more you drink
- Not being physically active
- Some hormonal factors, such as starting periods early, a late menopause, or long-term combined HRT
When does family history matter?
Having one older relative with breast cancer only slightly raises your own risk. Family history becomes more important when several close relatives on the same side of the family have had breast or ovarian cancer, when they were diagnosed young, or when a male relative had breast cancer.
If your family pattern suggests higher risk, your GP can refer you to a specialist family history or genetics clinic. They assess your risk and may offer earlier or more frequent screening, and in some cases genetic testing.
What are bRCA and other inherited genes?
We all carry BRCA1 and BRCA2 genes, which normally help protect against cancer. Some people inherit a faulty version, which significantly raises the lifetime risk of breast and ovarian cancer. Other genes, such as PALB2, can also increase risk. These inherited changes account for only a small share of all breast cancers.
People found to carry a high-risk gene change can be offered a range of options: enhanced screening (often including MRI scans from a younger age), medicines that lower risk, and, for some, risk-reducing surgery. Genetic testing and these decisions are always supported by specialist counselling, because they are personal and significant choices.
What you can do to lower your risk?
You cannot change your age or your genes, but a healthy lifestyle genuinely reduces breast cancer risk. Keeping to a healthy weight, being physically active, limiting alcohol and, for those who have children, breastfeeding where possible all help. Attending breast screening when invited does not prevent cancer, but it helps find it early when treatment works best.
What are the key takeaways?
- Only about 5 to 10% of breast cancers are caused by an inherited faulty gene.
- The biggest risk factors are being a woman and getting older — neither of which can be changed.
- Family history matters most when several close relatives were affected, or were diagnosed young.
- BRCA1, BRCA2 and PALB2 gene changes raise risk significantly; those affected can access extra screening and prevention.
- A healthy weight, regular activity and limiting alcohol all lower breast cancer risk.
Care like this is out of reach for millions
The diagnosis, screening and treatment described here are routine in the UK. In Pakistan, Indonesia and Malaysia, poverty puts them out of reach — so a treatable cancer too often becomes a fatal one. World Aid Network funds treatment through locally-licensed oncologists for patients who cannot pay.
Frequently asked questions
My mother had breast cancer — will I get it too?
Having one close relative with breast cancer raises your risk only slightly, and most people in this situation never develop it. Risk is higher if several close relatives were affected, especially at a young age, or if breast and ovarian cancer both appear in the family. If you are worried, your GP can assess your family history and refer you to a specialist clinic if needed.
Should I get a BRCA gene test?
Genetic testing is generally offered only to people whose personal or family history suggests a meaningful chance of carrying a high-risk gene change. It is not a routine test for everyone. A GP or genetics clinic can assess whether testing is appropriate for you, and it is always offered alongside specialist counselling.
Does drinking alcohol really increase breast cancer risk?
Yes. Alcohol is an established risk factor for breast cancer, and the risk rises the more you drink. Cutting down — or not drinking at all — is one of the lifestyle changes that lowers risk.
Can men inherit breast cancer risk genes?
Yes. Men can carry BRCA and other gene changes and can pass them on to their children. These changes raise a man's own (small) risk of breast cancer and his risk of some other cancers, such as prostate cancer, which is why a male relative with breast cancer is an important part of a family history.
This guide is general information, not medical advice. It was reviewed by the World Aid Network editorial team for accuracy against NHS and World Health Organization sources. Always speak to a GP or qualified clinician about your own health.