Can breast cancer be prevented?

Breast cancer is the most common cancer in the UK – one in eight women develop the disease at some stage in their lifetime.

Breast cancer is rare in men, with around 400 new cases diagnosed each year in the UK, compared with around 55,000 new cases in women.
Only three per cent of breast cancer cases are in women who carry genes that have been linked to the disease. Many of the factors that increase your chances of developing the disease are linked to your lifestyle.

What is breast cancer?

Breasts are made up of fatty connective tissue, milk-producing glands and ducts that carry milk from the glands to the nipple. Breast tissue naturally develops in response to hormones at different stages of life – for example, during puberty, pregnancy and breastfeeding.
Breast cancers almost always develop in the glands or ducts that produce milk and carry it to the nipple.
Cancers develop as a result of cells being damaged, which then grow uncontrollably, forming a lump or thickening called a tumour.
There are many different reasons why breast cancers develop, and hormones (particularly oestrogen) can influence the development and growth of some breast cancers. This means that life events that affect your hormone levels, such as pregnancy, can alter your cancer risk.
There are also other important risk factors that you can do something about, such as your diet and lifestyle choices.

Who is most at risk of breast cancer?

As with all cancers, the risk of developing breast cancer depends on a number of factors and varies from person to person.

Lifestyle risk factors

• Drinking alcohol
• Being overweight or obese (for post-menopausal breast cancer only)
• Adult weight gain
• Not doing enough physical activity
• Not breastfeeding when you have a baby

Other risk factors

• Age – your risk increases as you get older
• Greater weight at birth (pre-menopausal breast cancer only)
• Height – taller women are at greater risk
• Starting your period early (before age 12)
• Going through menopause late (over age 55)
• Not having children, or having a first pregnancy over the age of 30
• Family history – particularly if a close relative was diagnosed before the age of 50. If you are concerned about this, we recommend you speak to your doctor
• Taking combined hormone replacement therapy (the evidence is less clear for oestrogen-only HRT) – risk slightly increases the longer you take HRT, but decreases gradually once you stop
• Taking the oral contraceptive pill (the evidence is less clear for the mini pill) – risk slightly increases when you take the pill, but slowly returns to normal after you stop

If any of these apply to you, it does not mean that you will develop breast cancer – it just means that your risk may be higher than average. The good news is that there are steps you can take to reduce your risk.