A study looking for the best way to measure how well surgery for stomach cancer works (GASTROS)

Cancer type:

Stomach cancer





This study was done to find out which factors are most important when looking at how well surgery works for stomach cancer.

The study was open for people to join in 2019. The team published the results in 2021.

More about this trial

Doctors often use surgery to treat stomach cancer. Some people have part of their stomach removed (a partial gastrectomy). Some people have all of their stomach removed (a total gastrectomy).

When this study was done, doctors looked at several factors to decide how well surgery for stomach cancer has worked. These are called treatment outcomes. They include: 

  • whether they could remove all of the cancer
  • what side effects people had
  • how the operation affected people’s quality of life 

But different doctors used different treatment outcomes. This made it difficult to compare one operation or clinical trial with another.
In this study, doctors wanted to find out which treatment outcomes are best to use.  They wanted to form a list of the minimum number of factors doctors should look at. They would like all doctors and researchers to use the same list of outcomes. That way it is easier to compare the results of different trials.

The main aim of this study was to come up with a minimum list of treatment outcomes for people having surgery for stomach cancer.

Summary of results

Study design
This study was for people having surgery to remove all or part of their stomach. The research team also included health care professionals (HCPs) in the study.

The team looked at the results of other studies. And asked patients and HCPs what they thought was important. They then came up a list of possible treatment outcomes, and asked people to pick the most important ones to them.

The research team looked at 32 other studies and interviewed 20 patients to begin with. From this they had 498 different treatment outcomes. They grouped some together and simplified the list until there were 56 outcomes.

They then asked nearly 1,000 people to say which outcomes they felt were the most important. This included patients, surgeons and nurses.

After a final meeting to look at the results, they had a list of 8 treatment outcomes.

This included outcomes such as:

  • the side effects people have
  • whether the surgeons were able to remove all the cancer
  • how long people live
  • whether the cancer comes back 
  • the effect on diet and nutrition
  • overall quality of life

The research team would like this list to be used in all clinical trials looking at surgery for stomach cancer.

More detailed information
There is more information about this research in the reference below. 

Please note, this article is not in plain English. It has been written for health care professionals and researchers.

Core outcome set for surgical trials in gastric cancer (GASTROS study): international patient and healthcare professional consensus
B Alkhaffaf and others
British Journal of Surgery, 2021. Volume 108, Issue 10, pages 1216 to 1224.

Where this information comes from    
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link above is active and the article is free and available to view.

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 Bilal Alkhaffaf

Supported by

Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland
International Gastric Cancer Association – European Chapter
Manchester University NHS Foundation Trust
Medical Research Council (MRC)
NIHR Academy
University of Manchester

The GASTROS study was also supported by a number of national and international medical, nursing and patient support groups.

Other information

There is more information about this study on the GASTROS website.

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.

Wendy took part in a new trial studying the possible side effect of hearing loss

A picture of Wendy

"I was delighted to take part in a clinical trial as it has the potential to really help others in the future.”

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