A trial of radiotherapy for cancer that has spread to another part of the body (SABR-COMET)

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

Cancer type:

All cancer types
Cancer spread to the bone
Cancer spread to the brain
Cancer spread to the liver
Cancer spread to the lung
Secondary cancers




Phase 2

This trial is looking at stereotactic ablative radiotherapy (SABR) to treat cancer that has spread to another part of the body.

More about this trial

Sometimes cells can break away from cancer and spread to other parts of the body. When this happens it is called a secondary, or metastatic, cancer. Doctors usually treat these cancers with chemotherapy Open a glossary item, radiotherapy Open a glossary item or a combination of both. This is to slow down the growth of the cancer spread but not to cure it.

Research has suggested that when there are only a few areas of cancer spread, removing, or killing these areas can help control the cancer spread for a longer period of time.

Stereotactic ablative radiotherapy (SABR) is a way of giving radiotherapy to an area of cancer to target the treatment very accurately.

The researchers think SABR may be better than the standard treatment to treat these areas of cancer spread. To find this out they will compare SABR with standard treatment.

The aims of this trial are to find out

  • How well SABR works for cancer spread
  • What the side effects are
  • How it affects quality of life Open a glossary item

Who can enter

You may be able to join this trial if all of the following apply

  • Your original cancer (primary cancer Open a glossary item) was treated at least 3 months ago and there has been no sign of it getting worse since
  • Your cancer has spread to no more than 5 areas of your body
  • Your areas of cancer spread can be seen on a scan Open a glossary item (your doctor can tell you this)
  • You are well enough to carry out all your normal activities, apart from heavy physical work (performance status of 0 or 1)
  • You are at least 18 years old

You cannot join this trial if any of these apply. You

  • Have 3 or more areas of cancer spread in one area of your body, such as the lung, bones or liver
  • Have cancer spread only to your brain or you need surgery to remove the cancer that has spread to your brain
  • Have cancer spread in your thigh bone (femur)
  • Have an area of cancer spread the trial team feel they are unable to treat
  • Are able to have surgery to remove all the areas of cancer spread. If you previously had surgery to remove cancer spread and a scan shows it hasn’t been controlled and it can be treated with SABR you may be able to take part
  • Have previously had radiotherapy or radiofrequency ablation (RFA) Open a glossary item treatment for your cancer spread and a scan shows that it hasn’t been controlled
  • Are to have chemotherapy Open a glossary item or a biological therapy Open a glossary item to treat your cancer spread 4 weeks before having treatment, during treatment or within 2 weeks after treatment in this trial
  • Have had chemotherapy and there is no sign of cancer spread on a scan
  • Have a collection of fluid between the sheets of skin which covers your lungs (pleural effusion) that is caused by your cancer
  • Have an area of cancer that is causing pressure on your spinal cord (spinal cord compression Open a glossary item)
  • Have had an MRI scan Open a glossary item that shows an area of cancer within 3mm of your spinal cord
  • Are pregnant or breastfeeding

Trial design

This is a phase 2 trial. The trial team need 93 people to join.

It is a randomised trial. The people taking part are put into treatment groups by a computer. Neither you nor your doctor will be able to decide which group you are in.

  • People in one group will have stereotactic radiotherapy ablation (SABR)
  • People in the other group will have standard treatment

You have double the chance of being in the group that has SABR.

Before starting SABR, your doctor needs to plan where to give the radiotherapy. As a part of this you may need to have a radiotherapy mould made. This is used to keep a part of your body, such as your head, still during treatment. The mould will be used each time you have treatment.

You will also have a CT scan to confirm where and how big your areas of cancer spread are. The doctor will use this to target the areas more accurately and so reduce the amount of healthy tissue that is treated.

You have SABR every day, or every other day, Monday to Friday for 1 to 3 weeks. You have a CT scan before treatment each day. This is to see if the radiographer Open a glossary item needs to adjust your position for treatment.

After treatment with SABR your doctor may suggest you have chemotherapy. They will talk to you about this if necessary.

The trial team will ask you to fill out a questionnaire before you start treatment, after you finish treatment and then every 3 months for 2 years then every 6 months for a further 3 years. The questionnaire will ask about side effects and how you’ve been feeling. This is called a quality of life study.

Hospital visits

You see the doctor to have some tests before taking part in the trial. These tests include a physical examination, blood tests and one or more of the following scans

During treatment you see the doctor regularly to see how you are.

After treatment you see the doctor every 3 months for 2 years and then every 6 months for 3 years. You have a CT scan and a bone scan at 3 months, 6 months and then every 6 months.

Your doctor will then tell you how often they want to see you and how often you will have a scan.

Side effects

The side effects of having radiotherapy, including SABR, depend on the area of your body that is treated.

We have information on the side effects of radiotherapy.

The side effects of chemotherapy depend on the type of chemotherapy you have.

We have information on the side effects of chemotherapy.

The trial doctor will talk to you about the possible side effects of any treatment you have before you agree to take part in the trial.

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

Dr Stephen Harrow

Supported by

Experimental Cancer Medicine Centre (ECMC)
London Regional Cancer Programme (LRCP)
NIHR Clinical Research Network: Cancer
NHS Greater Glasgow and Clyde
Ontario Institute for Cancer Research (OICR)

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.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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