Causes of breast cancer in women

Who is more likely to get breast cancer

Anyone can get breast cancer and it's not always clear what causes it.

You might be more likely to get it if you:

• are over 50
• have dense breast tissue – you may be told this after a breast screening (mammogram)
• have other people in your family who've had breast or ovarian cancer – you may have inherited a faulty gene, such as a faulty BRCA gene
• have certain breast conditions, such as benign breast disease, ductal carcinoma in situ or lobular carcinoma in situ

You may also be more likely to get breast cancer if you have higher levels of the hormones oestrogen, progesterone or testosterone. This may be more likely if you:

• started your periods before you were 12, or went through the menopause after you turned 55
• have not given birth, or gave birth for the first time after 30
• did not breastfeed your children
• have used the contraceptive pill in the last 10 years, or take hormone replacement therapy (HRT) – these only slightly increase your risk and for many people the benefits of taking them outweigh the risks

Many breast cancers are also linked to lifestyle, such as smoking.

If you're trans or non-binary

If you're a trans man, trans woman or are non-binary, how likely you are to get breast cancer depends on if you've had surgery, and if you're taking hormones.

How to reduce your risk of getting breast cancer

You cannot always prevent breast cancer, but going for breast screening (mammogram) when you are invited can help find cancers that are too small to see or feel.

There are also things you can do to lower your chance of getting breast cancer.

Genetic testing for breast cancer risk

If any of your close relatives have had breast or ovarian cancer, you may be eligible for an NHS genetic test.

A genetic test will check to see if you have a faulty gene which increases your risk of getting cancer, such as a faulty BRCA gene.

Speak to a GP about genetic testing if breast or ovarian cancer run in your family.

The GP may ask about:

• who and how many people in your family have had cancer
• the type of cancer they had
• how old they were when they were diagnosed
• if your family member is available for genetic testing or has been tested before

The GP will refer you to a specialist breast clinic or genetics clinic for assessment if they think you are at increased risk.

You can also have NHS genetic testing for faulty BRCA genes if you're 18 years or older and have 1 or more Jewish grandparent.

Find out more

• Predictive genetic tests for cancer risk genes
• Cancer Research UK: family history of breast cancer and inherited genes
• The NHS Jewish BRCA testing programme

Treatments if you're at increased risk

If you have a higher risk of getting breast cancer because you have a faulty gene, there are some treatments that can help reduce your risk.

A doctor or genetic counsellor will discuss your options with you and explain the benefits and possible side effects.

Treatments to reduce your risk include:

• medicines
• surgery to remove your breasts (mastectomy) – this may be offered if you are at very high risk