Breast Cancer Screening - The Facts

Date: 15 October 2018

What is it?

Breast cancer screening is one of the UK’s three national cancer screening programmes designed to catch cancers early, while they are easier to treat.  Every three years, women between 50 and 70 are invited to attend a mammogram where a female mammographer takes two X-rays of each breast using a mammogram machine. Whether or not you accept your mammogram invitation is up to you. There are benefits and risks to the process that we’ll help you weigh up as you read on.

Who’s eligible?

Women aged between 50 and 70 years old who a registered with their local GP will be automatically sent a screening invitation via a letter in the post. Women over 70 don’t get automatically invited to for a mammogram, but they can drop into their local breast screening unit and request a mammogram once every three years. They will also be given cards at these appointments to help them remember to book their next appointment.

Why is it important?

While screening doesn’t prevent you getting breast cancer in the first place, it does has the potential to save lives by finding breast cancers at an early stage. Mammograms are designed to pick up tumours when they're too small to see or feel. As well as this, detecting cancers while they are smaller means there’s less chance you’ll need a mastectomy or chemotherapy when it comes to treatment.

Are there any downsides?

You may have heard of the term ‘over diagnosis’ being used in relation to the breast cancer screening programme. This describes the process where some, very slow growing cancers - the type which wouldn’t actually cause harm if left untreated, are found during screening. This means the woman will be told she has cancer, which can be very distressing, as well as potentially receiving invasive and uncomfortable treatment when really she didn’t need to. It may be useful to be aware that this can happen before you attend your breast cancer screening appointment. The best estimate is that for every life saved by screening three women will undergo treatment unnecessarily. 1 
There’s also a small chance that you may receive a negative result when cancer is in fact present. Breast cancer screening picks up most breast cancers, but it can miss cancer in about 1 of 2,500 women screened . Furthermore, breast cancers can develop in the three years between mammograms – so, it’s important to look out for the signs and symptoms of breast cancer in-between mammograms. 

And what about the benefits?

The earlier breast cancer is found, the better the chances of surviving it are. Detecting tumours while they are smaller also means there’s less chance you’ll need a mastectomy or chemotherapy. Breast screening saves about 1,300 lives from breast cancer each year in the UK and approximately 107 in Yorkshire. 2, 3  

Our advice

Yorkshire Cancer Research recommends women do take part in breast cancer screening. Despite the very small risks of missed diagnosis or over diagnosis, this programme is designed to save lives and is recognised for its success in this. A few minutes of discomfort is all it takes to save many women from dying early from breast cancer.

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

If you're concerned about breast cancer symptoms, like a change in your nipple or breast appearance or you find a lump – make an appointment with a doctor straight away.
For more information on breast cancer screening, you can take a look at our information leaflet here.



  1. The Independent UK Panel on Breast Cancer Screening, 2012. The Benefits and Harms of Breast Cancer Screening: An Independent Review.  
  3. Assumes Yorkshire population is 8.2% of the UK population


Nikki Brady, Senior PR Officer, Yorkshire Cancer Research. Tel: 01423 877228. Email:

Notes to Editors

  • Harrogate-based Yorkshire Cancer Research was founded in 1925 and is the largest independent regional cancer charity in England (Registered Charity 516898). We are not part of a national charity.
  • We are committed to reducing the devastating impact of cancer on the lives of people living in Yorkshire.
  • Our mission is to work in partnership, fund research and support initiatives that will help people in Yorkshire avoid, survive and cope with cancer.
  • Current statistics show that 575 people are diagnosed with cancer in Yorkshire every week. Incidence and mortality rates are higher than the England average due to social deprivation, post-industrialisation and lifestyle choices but also availability of healthcare services and difficulties accessing early diagnostics, clinical trials and the latest treatments.
  • We aim to:
    • Be the leading authority on cancer in Yorkshire, understanding the problems and priorities in the region and sharing knowledge with partners.
    • Raise awareness of cancer and how to prevent it by working in local communities, schools and colleges, sports clubs and with other health-related organisations.
    • Promote screening programmes and fund research that can improve the diagnosis of cancer so we can detect and treat it at the earliest opportunity.
    • Invest in innovative research projects at every stage of a cancer patient's journey.
    • Campaign for fair and equal access to the very best healthcare services and a greater share of the money spent nationally on research.
  • For further information, please visit or follow us on Facebook or Twitter.

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