Breast cancer screening: the facts

15 October 2018

What is it?

Breast screening aims to find breast cancers early, often when they are too small to see or feel.  A type of x-ray, called a “mammogram”, is used to take images of each breast. Finding cancers early means they are often easier to treat and there is a greater chance of a full recovery. However, there are both benefits and risks to breast screening as explained below.

Who’s eligible?

Women aged 50 to 70 years old (up to 71st birthday) will be invited for breast screening every 3 years. As long as you are registered with a GP, you will receive a letter through the post with an appointment time and place. It is important that your GP has up to date contact details for you so you receive the invitation.

Women aged 71 and over don’t get automatically invited to breast screening, but you can still arrange an appointment every 3 years via your GP or directly with your local breast screening unit. The contact details for local breast screening units can be found here.

Why is screening important?

While screening doesn’t prevent breast cancer, it does have the potential to save lives by finding breast cancers at an early stage.

Finding breast cancer early often means it is easier to treat and the chances of a full recovery are greater. It can also mean that less aggressive treatments are needed (such as a mastectomy or chemotherapy).

It’s estimated that for every 200 women screened, 1 woman has their life saved and will not die from breast cancer. This means breast screening saves about 1,300 lives each year in the UK and approximately 100 lives in Yorkshire. 1,2

Are there any downsides?

Following breast screening, some women will be diagnosed with a breast cancer that would never have been found without screening and would never have gone on to cause them harm – this is called ‘overdiagnosis’. 

Being diagnosed with cancer can be very distressing, for both the individual and their family, and having an ‘overdiagnosed’ cancer could mean you have treatment that isn’t needed. However, at the moment, there is no way of knowing which cancers are harmful and need treating, and which are unlikely to cause harm and can be left without treatment. Therefore, appropriate treatment options are explored and offered to everyone. It’s estimated that for every 200 women screened every 3 years between the ages of 50 and 70, 3 will have an ‘overdiagnosed’ cancer3

There’s also a small chance that you may receive a negative result when cancer is in fact present. Breast screening picks up most breast cancers, but very occasionally cancers will be missed.

For most women, the mammogram can be uncomfortable, and some women will find it painful. The mammography practitioners are used to screening women of all sizes and will do their best to minimise any discomfort. Research has shown that for most women it's less painful than having a blood test and compares with having blood pressure measured4. The mammogram itself only lasts a few minutes and could save your life. 

Our recommendation

Yorkshire Cancer Research recommends women take part in breast cancer screening. Despite the very small risks of missed diagnosis or overdiagnosis, the programme is designed to save lives and is recognised for its success. Without it, fewer women would be diagnosed with an early-stage cancer and more women would die of breast cancer each year. Breast screening saves lives.

I’m worried about a change in my breast – but it’s ages until my next screening appointment

If you're worried about breast cancer symptoms, such as a change in your nipple or breast appearance or you find a lump – make an appointment with a doctor straight away. Do not wait until your next screening appointment. More information on symptoms of breast cancer can be found here.

The content of this article was reviewed and updated in October 2021.


  2. Assumes Yorkshire population is 7.74% of the UK population
  3. The Independent UK Panel on Breast Cancer Screening, 2012. The Benefits and Harms of Breast Cancer Screening: An Independent Review.  

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