Does breast size affect breast cancer risk?

Are bigger breasts more likely to get cancer?

Breast size is not one of the things the NHS lists as making breast cancer more likely. The NHS says anyone can get breast cancer and it is not always clear what causes it. The factors it does list are:

• being over 50
• having dense breast tissue
• having close family who have had breast or ovarian cancer, which may mean an inherited faulty gene such as BRCA
• certain breast conditions, such as benign breast disease, ductal carcinoma in situ or lobular carcinoma in situ
• higher levels of hormones such as oestrogen

The World Health Organization’s list is similar: increasing age, obesity, harmful use of alcohol, family history, past radiation exposure, reproductive history, tobacco use and hormone therapy after the menopause. Breast size is not on it.

Sources: NHS: Causes of breast cancer in women; World Health Organization: Breast cancer fact sheet

What is the difference between breast size and breast density?

Breast density describes how much fibrous and glandular tissue the breast has compared with fatty tissue. Manchester University NHS Foundation Trust explains that women with denser breasts are known to face a higher risk of breast cancer.

So density is about what the breast is made of, not how big it is. NHS 111 Wales says you may be told you have dense breast tissue after breast screening (a mammogram).

Sources: Manchester University NHS Foundation Trust: Breast density clue for cancer risk (2026); NHS 111 Wales: Cancer of the breast, female

Can you get breast cancer with small breasts?

Yes. The NHS says anyone can get breast cancer, including women, men, trans and non-binary people.

Men tend to have a much smaller amount of breast tissue than women, but breast cancer can still develop, explains the Humberside Breast Screening Service at Hull University Teaching Hospitals NHS Trust. NHS inform says breast cancer in men can develop in the small amount of breast tissue behind the nipples.

Sources: NHS: Why breast screening is done; Hull University Teaching Hospitals NHS Trust (Humberside Breast Screening Service): Breast cancer in men; NHS inform (Scotland): Breast cancer in men

Does breast size affect breast screening?

The NHS says you can have breast screening whatever size or shape your breasts are. Regular screening is one of the best ways to spot a cancer that is too small to feel or see.

In England, NHS breast screening is offered to women aged 50 up to their 71st birthday, with an invitation every 3 years.

Sources: NHS: Why breast screening is done; NHS: Who breast screening is for

Which breast changes should you get checked?

The NHS says it is common for breasts to be different sizes, so check for changes that are not normal for you. See a GP or doctor if you notice:

• a lump or swelling in your breast, chest or armpit
• a change in the skin of your breast, such as dimpling (it may look like orange peel)
• a change in skin colour – on white skin it may look red, on black or brown skin it may look darker than usual
• a change in the size or shape of one or both breasts
• nipple discharge (if you are not pregnant or breastfeeding), which may have blood in it
• a change in the shape or look of your nipple, such as it turning inwards or a rash on it

Having these symptoms does not definitely mean you have breast cancer, but it is important to get checked.

Sources: NHS: How to check your breasts or chest; NHS: Symptoms of breast cancer in women