A trial to find out how long to give chemotherapy after surgery for bowel cancer (SCOT)

Cancer type:

Bowel (colorectal) cancer
Colon cancer
Rectal cancer




Phase 3
This trial compared 3 months with 6 months of chemotherapy for people who had surgery for bowel (colorectal) cancer. 
It was for people who had 1 of the following:
  • cancer that had spread to the lymph nodes Open a glossary item (stage 3 bowel cancer)
  • stage 2 bowel cancer that had a high risk of coming back.
Cancer Research UK supported this trial. 

More about this trial

Doctors often treat bowel cancer with chemotherapy after surgery. This helps to stop the cancer coming back. People usually have treatment for 6 months. But when the researchers did this trial, research had suggested that 3 months would work as well. 
Unfortunately, all chemotherapy drugs have side effects and many of them can get worse as the treatment goes on. One of the main side effects is nerve damage which causes numbness or tingling in people’s fingers and toes. The researchers hoped that giving 3 months of chemotherapy instead of 6 would cause fewer side effects.
The aims of this trial were to:
  • find out if 3 months of chemotherapy worked as well as 6 months
  • see if 3 months of chemotherapy had fewer side effects
  • learn more about the side effects

Summary of results

The researchers found that shortening treatment to 3 months did not affect the chance of cancer coming back for many people. The shorter treatment time also reduced side effects.
The researchers published these results in March 2018. 
This phase 3 trial took place worldwide. 6,088 people took part in this trial.
The chemotherapy drugs they had depended on their individual situation. People taking part had standard chemotherapy Open a glossary item. They had 1 of the following combinations of chemotherapy:
  • oxaliplatin, 5FU and folinic acid (this is called FOLFOX)
  • oxaliplatin and capecitabine (this is called XELOX or CAPOX)
1,981 people had FOLFOX and 4,107 people had CAPOX.
They were then put into 1 of 2 groups at random, and:
  • 3, 044 had 3 months of chemotherapy
  • 3, 044 had 6 months of chemotherapy
The researchers looked at whose cancer had come back or died. After a minimum of 3 years follow up, this happened in:
  • 740 people who had 3 months of chemotherapy
  • 742 people who had 6 months of chemotherapy
Side effects
People who had 6 months of treatment had more serious side effects that included:
  • diarrhoea
  • a drop in white blood cells Open a glossary item 
  • pain
  • redness of the palms of the hand or soles of the feet (hand foot syndrome)
  • nerve damage (peripheral neuropathy Open a glossary item)
Just under 6 out of 10 people (58%) who had 6 months of treatment reported severe nerve damage. Between 2 and 3 people out of 10 (25%) who had 3 months of treatment reported severe nerve damage. 
When the researchers looked at the quality of life questionnaires Open a glossary item they found that people with nerve damage had a poorer quality of life as a result. So, having treatment for 3 months halved the number of people who had severe nerve damage. 
The trial team are continuing to follow up the people who took part for longer term survival. They hope to have these results available in 2019.
The researchers found that 3 months of treatment worked as well as 6 months to stop the cancer coming back. And people who had 3 months of treatment had fewer side effects. 
The researchers suggest that 3 months of chemotherapy after surgery should be a new standard of care for many patients
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 Tim Iveson

Supported by

Cancer Research UK
Cancer Research UK Clinical Trials Unit, Glasgow
Oncology Clinical Trials Office (OCTO), Oxford
Experimental Cancer Medicine Centre (ECMC)
Medical Research Council (MRC)
NIHR Evaluation, Trials and Studies Coordinating Centre (NETSCC) 
NIHR Clinical Research Network: Cancer
Scottish Cancer Research Network
NHS Greater Glasgow and Clyde
University of Glasgow
Danish Colorectal Oncology Group 
Vall d’Hebron University Hospital and Institute of Oncology (VHIO) 
Universitat Autònoma de Barcelona (UAB)
Australasian Gastro-Intestinal Trials Group (AGITG)
Swedish Society of Gastrointestinal Oncology


If you have questions about the trial please contact our cancer 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.

Last reviewed:

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