What is breast screening?

Breast cancer screening is a way of finding breast cancers early, when they are small. When breast cancer is diagnosed early, less treatment may be needed, and treatment is more likely to be effective.

The first stage of breast screening is a breast x-ray (mammogram) of each breast. About 96 out of every 100 women who go for screening (96%) have a normal result.

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About breast cancer

Breast cancer is the most common type of cancer in women. As women get older, their risk of developing breast cancer increases. Most breast cancers are diagnosed in women over 50 years old.

Breast cancer treatments are improving all the time. Over 3 out of 4 women diagnosed with breast cancer (78%) are alive 10 years later.

Breast screening age

Every year, around 2.5 million women in the UK have screening with an NHS Breast Screening Programme. Women aged between 50 and 70 who are registered with a GP are invited for a mammogram. This happens every 3 years.

In England, a research trial is looking at extending the age range to include women aged 47 to 49 and 71 to 73. Most local breast screening centres in England are taking part. If you live in England, you may be invited to have breast screening as part of this trial.

If you have any symptoms of breast cancer, see your GP. Do not wait for a breast screening invitation.

If you are under 50

Women under 50 are not routinely invited for breast screening. This is because breast cancer is much less common in women in this age group. Mammograms are also less reliable before the menopause, which usually happens around the age of 50. After the menopause, breast tissue is less dense. There is more fatty tissue and less glandular and connective tissue. This makes mammograms easier to read.

Women under 50 who have a family history of breast cancer may be offered regular screening. We have more information about breast screening for women with a family history of breast cancer.

There are also some rare types of inherited conditions that can increase the risk of breast cancer. If you have one of these conditions, you may also be offered screening under the age of 50. 

If you are over 70

If you are over 70, you can still have screening. This is because you are still at risk of breast cancer. You will not get an invitation letter unless you are part of the trial mentioned above. But you can contact your local screening unit every 3 years to arrange a mammogram.

You can ask your GP where your local screening unit is. Or you can search on the NHS website.

If you are trans or non binary

If you are trans or non-binary, talk to your GP or practice nurse about breast screening. The NHS Breast Screening Programme only automatically invites people who are registered as female with their GP. But your GP can contact the NHS Breast Screening Programme, so you can be invited for screening appropriately.

If you are a trans man and have not had surgery to remove the breast tissue, it is a good idea to think about having breast screening. If you have had surgery but have some remaining breast tissue, you can also consider screening.

If you are a trans woman taking hormones, it is a good idea to think about having breast screening. This is because taking hormones may slightly increase the risk of breast cancer.

If you are worried about having breast screening, contact your local breast screening unit. They can help support you. The NHS has more information about screening for trans people. The LGBT Foundation can also give you confidential advice and support.

Getting your appointment

Your invitation for breast screening comes by letter with information about your appointment and what to expect. We have more information about getting your breast screening appointment. This includes information if you:

  • need an interpreter
  • have breast implants
  • have been treated for breast cancer.

We also have information on the main benefits and disadvantages of breast screening. This might help you decide if you want to have breast screening.

What happens during the appointment?

A breast screening appointment usually takes about 30 minutes. When you arrive, you will meet the receptionist or the person doing the mammogram (mammographer or radiographer). They will check your name, date of birth and address. The mammogram is done by female staff.

They will ask you questions about your health and whether you have had any breast problems. The mammographer will explain how the mammogram images are taken and can answer any questions you have. If you are happy with this, you will then have your mammogram.

The staff are trained to reassure and support you. If you feel it would help, you may be able to bring someone with you. Contact the screening unit before your appointment to arrange this. Men are not usually allowed in the screening area, but can wait in the waiting room.

Getting your screening results

You usually get your breast screening results, in writing, about 2 to 3 weeks after your mammogram. A copy is also sent to your GP. If you have not heard anything after 3 weeks, call your breast screening unit and ask them to check your results.

Your results letter will tell you one of the following:

  • Your mammogram is normal, and you will be invited again for screening in 3 years if you are still of screening age. About 96 out of every 100 women who have breast screening (96%) have a normal result.
  • You are invited for a repeat mammogram. This can happen if the mammogram has missed part of the breast tissue, the x-ray picture is blurred or there is a problem with the equipment (but this is rare).
  • You are invited to a breast assessment clinic for further tests. This happens to about 4 out of every 100 women who have breast screening (4%). But around 3 out of 4 women who have further tests (75%) do not have breast cancer.


Results of breast screening

Further tests

If you need more tests, you will be asked to go to a breast assessment clinic. The clinic staff will explain why you have been invited back and which tests you need. You can usually have the tests and get the results on the same day. But you may have to go back to the clinic for the results.

At the clinic, you will see a specialist doctor, specialist nurse or radiographer. They usually ask you if you have had any breast problems or if anyone in your family has had breast cancer.

The doctor or nurse will examine the breasts and the lymph nodes under the arm. They will arrange some more tests. These may include the following:

  • Mammogram

    You may have more mammograms that focus on one area of the breast. These can be taken from different angles or made bigger. This is to make the image of the area clearer.

  • Breast ultrasound

    You may have a breast ultrasound. Some women also have an ultrasound of the lymph nodes in the armpit.

  • Breast biopsy

    If an abnormal area is found in the breast, the doctor will need to take a sample of cells (biopsy). There are different ways of taking a biopsy.

Waiting for results

Waiting for test results can be a hard time. You may find it helpful to talk to a partner, family member or close friend. You can also contact the breast unit where you had your tests. You can also talk to one of our cancer support specialists on 0808 808 00 00.

Possible test results

A doctor or breast care nurse at the assessment clinic will give you the results of your tests. Some of the possible results include the following.

No problem seen

This means the first mammogram showed an abnormal area in the breast, but further tests did not find a problem. The first mammogram result is called a false-positive result.

You will not need to have any further tests or treatment. You will be invited back for a routine mammogram in 3 years if you are still of screening age.

Many false-positive results are caused by tiny deposits of calcium in the milk ducts. This is called microcalcification. This happens in many women over the age of 50. It is usually harmless. We have more information about breast calcifications.

Benign condition (not cancer)

Some women will be told they do not have cancer, but have a benign (non-cancerous) condition. Many benign conditions of the breast can be seen on a mammogram. You may be referred to a breast specialist for advice, monitoring or treatment.

Breast cancer

Only about 8 in every 1,000 women who have breast screening (less than 1%) will be diagnosed with breast cancer. If your tests show you have cancer, you will be referred to a breast surgeon.

Most breast cancers are invasive. This means the cancer cells have spread outside the lining of the ducts or lobes into surrounding breast tissue. However, 1 out of 5 breast cancers found by screening (20%) are ductal carcinoma in situ (DCIS). DCIS is the earliest form of breast cancer.

Your surgeon, cancer doctor or nurse will give you more information about the diagnosis. They will talk to you about what will happen next and about your treatment options. We have more information about breast cancer and DCIS.

Breast awareness

It is important to still check your breasts for any symptoms of breast cancer even if you attend regular breast screening. If you notice any symptoms, or anything unusual for you, contact your GP.

About our information

  • References

    Below is a sample of the sources used in our breast cancer information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    European Society for Medical Oncology. Primary breast cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Annals of oncology 26 (supplement 5): v8–v30. 2015.

    Morrow M, et al. Chapter 79: malignant tumors of the breast. DeVita, Hellman and Rosenberg’s cancer: principals and practice of oncology (10th edition). Lippincott Williams and Wilkins. 2014.

    National Institute for Health and Care Excellence (NICE). Early and locally advanced breast cancer: diagnosis and management. July 2018.

    Scottish Intercollegiate Guidelines Network. SIGN 134. Treatment of primary breast cancer: a national clinical guideline. September 2013.

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr Rebecca Roylance, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.