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

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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

Status:

Results

Phase:

Phase 2

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

It was open for people to join between 2012 and 2016, and the team published the results in 2019.

More about this trial

Sometimes cancer cells move away from the original (primary) cancer and spread to other parts of the body. When this happens it is called secondary, or metastatic, cancer. 

When this trial was done, doctors often treated cancer that had spread with chemotherapy or radiotherapy, or a combination of the two. The aim of this treatment is to slow down the growth of the cancer rather than cure it.

Research has suggested that when there are only a few areas of cancer spread, treating these specific areas can help control the cancer for longer.

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

Some people in this trial had standard treatment, and some had SABR. The researchers hoped that SABR may be better than the standard treatment for people whose cancer has spread. 

The main aims of this trial were to find out:

  • how well SABR works for cancer that has spread
  • more about the side effects 
  • how it affects people’s quality of life

Summary of results

The results showed that stereotactic ablative radiotherapy (SABR) helped stop cancer growing and meant people lived longer. But it also caused more side effects.

Trial design
Everyone taking part in this trial had cancer that had spread to up to 5 other areas of the body. These areas included the lungs, bone and liver.

The people who joined the trial were put into 1 of 2 treatment groups at random. There were twice as many people in the SABR group as there were in the standard treatment group. This is called 2:1 randomisation.

Results
A total of 99 people joined this trial and were put into 1 of 2 treatment groups. There were:

  • 33 people in the standard treatment group
  • 66 people in the SABR group

The people taking part had cancer that had spread to between 1 and 5 other areas of the body:

  • 1 area in 42 people
  • 2 areas in 32 people
  • 3 areas in 18 people
  • 4 areas in 4 people
  • 5 areas in 3 people

The research team looked at how long it was before people’s cancer started to grow again. They found it was longer for people who had SABR:

  • 6 months for those who had standard treatment
  • 12 months for those who had SABR

They then looked at how long people lived for, and found this was also longer for people who had SABR:

  • 28 months for those who had standard treatment 
  • 41 months for those who had SABR


When they looked at how many people had died, they found this was lower in the SABR group:

  • 16 out of 33 people (48%) who’d had standard treatment
  • 24 out of 66 people (36%) who’d had SABR

The research team looked at the change in size of 157 specific areas of cancer, to see if they’d grown after treatment or not. The number of areas of cancer that had not grown was:

  • 28 out of 57 (49%) in the standard treatment group
  • 75 out of 100 (75%) in the SABR group

Quality of life
The research team measured changes in people’s quality of life using several different questionnaires. The people taking part completed these questionnaires before, during and after treatment. 

The research team found there wasn’t any difference in the results between those who had standard treatment and those who had SABR.

Side effects
People in both groups had some side effects. But more people who had SABR had moderate or severe side effects:

  • 3 people (9%) who had standard treatment
  • 19 people (29%) who had SABR

Doctors think 3 people who had SABR died because of the treatment, rather than because their cancer had grown. Two had lung infections and one died following an operation to help with a stomach ulcer caused by the radiotherapy. 

No one in the standard treatment group died because of the treatment they had.

Conclusion
The research team concluded that SABR did help stop the cancer growing and meant that people lived longer. But it also caused more side effects.

They recommend that more trials are done to find out more about how well SABR works for specific cancer types. And that it might to useful to find out if there is a maximum number of areas of cancer spread where SABR is helpful.

Where this information comes from    
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.

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)

Freephone 0808 800 4040

Last review date

CRUK internal database number:

13007

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

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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