Breast cancer screening
Breast cancer screening uses a test called mammography which involves taking x-rays of the breasts. Screening can help detect breast cancers early when they are too small to see or feel. These tiny breast cancers are usually easier to treat than large ones.
Women who are diagnosed with breast cancer at the earliest possible stage have a nine in ten chance of surviving for at least five years after diagnosis.
Who is invited for breast screening?
Across the UK women aged 50 to 70 are invited for breast screening with mammography every three years. Women over 70 are eligible for breast screening but are not automatically invited. In England a trial is taking place to look at the possible benefits of extending breast screening so that women aged 47 to 49 and 71 to 73 are also invited.
How many lives does breast screening save?
An independent review of breast screening (IBSR) found that breast screening saves around 1,300 lives from breast cancer in the UK each year.
What are the harms of breast screening?
Breast screening is not perfect. As well as picking up cancers that need treating, it also picks up invasive breast cancers that will not cause any problems in a woman's lifetime and early stage non-invasive breast cancers called Ductal Carcinoma in Situ (DCIS).
The IBSR also found that each year in the UK screening leads to around 4,000 women diagnosed and treated for a breast cancer that never would have caused them any harm during their lifetime. These women have been ‘overdiagnosed’.
At the moment it is not possible for doctors or patients to be certain whether a breast cancer will grow quickly and needs treating, or will grow slowly and not cause any harm. Almost all women with breast cancer are treated with surgery and many also have radiotherapy, hormone therapy and chemotherapy.
Other harms from breast screening include exposure to small amounts of radiation from x-rays, false negative and false positive results. False positive results, in particular, can lead to anxiety as women await the results of further tests to determine whether or not they have breast cancer.
What is the balance of benefits and harms?
There are 15,500 breast cancers diagnosed through screening in the UK each year. Of these, 4,000 will be 'overdiagnosed' (diagnosed with a breast cancer that would not have caused them any harm) , and 1,300 lives are saved.
This means that for every life saved from breast cancer by screening, around three women are overdiagnosed.
Should I go for breast screening?
Whether or not to go for breast screening is clearly a personal decision. It’s important that women have access to enough information about benefits and harms of breast screening in order to make that decision.
Breast screening remains one of the best ways of detecting breast cancer at an early stage when treatment is likely to be most effective. But along with the reduced risk of dying from breast cancer come harms. The most significant of these harms is the chance of being diagnosed and treated for a breast cancer that would not have caused any problems.
What if I'm not aged 50 to 70?
Breast screening is not routinely available to women under 50. This is because there is less evidence that screening women in their early 40s will be of benefit. The breasts of younger women are more dense which makes it difficult to identify areas which could be cancer.
Women with a family history of breast cancer may be eligible for screening before the age of 50. If you have a family history of breast cancer, do talk to your GP who will refer you to specialist services if necessary.
All women over 70 are entitled to breast screening although they are not automatically invited. To make an appointment, talk to your GP or breast screening unit.
There is a trial underway at the moment to look at whether breast screening should be extended to include women from age 47-49 and 71-73. Some women in these age groups will also be invited for screening.
Our current research
Cancer Research UK continues to fund research to improve the effectiveness of the national breast cancer screening programme.
To read about our research into breast cancer screening, go to our research highlights pages.
Find out more
- CancerHelp UK, our patient information website answers your questions about mammography
- Find statistics about breast screening on our CancerStats pages
- Our 'how do we know' page about the evidence about breast screening.
When it comes to finding cancer early, screening is only one part of the story. As well as attending screening, you can help to spot breast cancer early by being breast aware and looking out for any unusual changes.
There are many factors which affect a woman’s risk of developing breast cancer. Things we can do to reduce the risk of breast cancer include:
Question about cancer? Contact our information nurse team