A trial looking at the benefit of radiotherapy after mastectomy for breast cancer (Supremo trial BIG 2-04)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Breast cancer




Phase 3

This trial is trying to find out if radiotherapy (after surgery to remove the breast) helps to stop breast cancer coming back in women who have an ‘intermediate risk’ of recurrence.

Doctors usually treat breast cancer with surgery, sometimes followed by chemotherapy, hormone therapy or radiotherapy, or a combination of these treatments. The treatment will depend on the stage of the cancer, and the likelihood that the cancer will come back in the future.

Some women who have surgery to remove their breast (a mastectomy) have breast cancer at ‘high risk’ of coming back. They have radiotherapy to help stop this happening. Women with breast cancer at ‘low risk’ of coming back after a mastectomy don’t need radiotherapy.

Some women with breast cancer at ‘intermediate risk’ of coming back after a mastectomy have radiotherapy, and some don’t. But doctors aren’t really sure whether it helps or not. All treatments have some side effects, so it is important that women don’t have treatment they don’t need.

The aim of this trial is to find out if radiotherapy is necessary to stop intermediate risk breast cancer coming back after a mastectomy. And to see how radiotherapy affects quality of life for this group of women.

Who can enter

You can enter this trial if you are a woman and you have

  • Breast cancer that is classed as intermediate risk of coming back after surgery (your doctor will be able to tell you more about this)
  • Have had your breast cancer completely removed with a mastectomy (you can still take part if you have had breast reconstruction or if you had chemotherapy before your operation)
  • Are well enough for radiotherapy, and for chemotherapy and hormone therapy if you need them
  • Had cancer in between 0 and 3 lymph nodes

You cannot enter this trial if you

  • Have breast cancer that is classed as either low risk or high risk of coming back after surgery
  • Have just had the area of cancer of removed (a lumpectomy), and not your whole breast
  • Had breast cancer that was 2cm or smaller and had not spread to the lymph nodes
  • Have breast cancer that has spread to another part of the body (metastasised)
  • Had cancer in 4 or more lymph nodes
  • Have cancer in both breasts (bilateral breast cancer)
  • Have had any other cancer in the past, apart from non melanoma skin cancer or carcinoma in situ of the cervix
  • Are pregnant

Trial design

This is a randomised trial. It will recruit 1,600 women into 2 groups. The women taking part will be put into treatment groups by a computer. Neither you nor your doctor will be able to decide which group you are in.

All women will have some treatment after their mastectomy. This could be hormone therapy, chemotherapy or both.

If you are in group 1 you will also have radiotherapy to the chest wall Open a glossary item. You have treatment once a day (Monday to Friday) for 3 to 5 weeks. The actual treatment will take a few minutes each time.

If you are in group 2 you won’t have radiotherapy.

You may be asked to fill out a questionnaire before you start treatment and then at 1 year, 2 years, 5 years and 10 years. This will ask you how you have been feeling and about any side effects you have had. It is called a quality of life questionnaire.

The research team are running a health economics sub study as part of this trial. This means they want to find out if giving radiotherapy as well is cost effective. If you take part in this you will need to complete a diary recording every visit you make to a health professional until 5 months after surgery or until you finish chemotherapy.

The research team would also like to store a sample of your cancer and of your blood. They would like to use the samples in their research to find out more about breast cancer. You don’t have to do this - you can still take part in the rest of trial if you decide not to agree to this.

Hospital visits

You will see the doctor and have some tests before you start the trial. These tests include

  • Mammogram
  • Blood tests
  • Physical examination
  • Chest X-ray

You may have chemotherapy or hormone therapy (or both) after your operation. If you do, your doctor will tell you about the specific drugs you will have, and how often you need to go to hospital.

You will see the doctors again before and after your course of radiotherapy (or at a similar time if you do not have radiotherapy).

If you are in group 1 you will go to the hospital every week day for 3 to 5 weeks to have radiotherapy.

After treatment, everyone taking part in the trial will see the doctors and have a physical examination once a year for 10 years. You will have a mammogram at least once every 2 years for 10 years.

Side effects

The side effects of radiotherapy depend on the area of the body being treated. The side effects of radiotherapy for breast cancer include

  • Soreness or redness of the skin
  • Tiredness
  • Lymphoedema
  • Slightly darker skin

Rarely, you can become short of breath due to radiation fibrosis in your lungs. Or perhaps have rib fractures in the future because of damage to your ribs.

We have more information about the side effects of radiotherapy for breast cancer.

There is more information about this trial on the Supremo trial website.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Prof Ian Kunkler

Supported by

Breast International Group (BIG)
European Organisation for Research and Treatment of Cancer (EORTC)
Experimental Cancer Medicine Centre (ECMC)
Medical Research Council (MRC)
NIHR Clinical Research Network: Cancer
Trans Tasman Radiation Oncology Group

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

A picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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