A trial comparing keyhole surgery with open surgery for people with lung cancer (VIOLET)

Cancer type:

Lung cancer
Non small cell lung cancer
Small cell lung cancer





This trial compared open surgery with keyhole surgery Open a glossary item for lung cancer that hadn’t spread. They used a method of keyhole surgery called video assisted thoracoscopic surgery (VATS).

The trial was open for people to join between 2015 and 2019. The team published the results in 2022.

More about this trial

Doctors sometimes use surgery to treat lung cancer that hasn’t spread to another part of the body. They often remove one part of the lung (a lobe). This is called a lobectomy. 

There are 2 main ways to do this.

The first is open surgery. This is where the surgeon makes one larger cut in the back or the side of the chest. 

The second is keyhole surgery. The surgeon makes between 1 and 4 small cuts in the chest. They put a camera (thoracoscope) through one cut. And the surgical tools through the same cut or the other cuts. The method they used in this trial was video assisted thoracoscopic surgery (VATS).

When this trial was done, surgeons were using both open surgery and keyhole surgery. Researchers wanted to find out which was best.

The main aims of this trial were to find out:

  • how the different types of surgery affect people’s quality of life
  • more about the side effects
  • how well each type of surgery works

Summary of results

This trial team found that VATS should be used to treat early stage lung cancer. 

Just over 500 people joined this trial. They all either had lung cancer, or their doctors thought they may have lung cancer. They were due to have surgery to remove a section (lobe) of their lung.

They were put into a treatment group at random:

  • half had open surgery
  • half had video assisted thoracoscopic surgery (VATS)

Quality of life
The trial team looked at a number of factors and found that:

  • pain levels on the first day were the same in both groups
  • pain levels after that were lower in the VATS group
  • people who had VATS needed fewer painkillers
  • overall quality of life was higher for those in the VATS group
  • people who had VATS had fewer complications from surgery
  • people who had VATS had a shorter stay in hospital

Side effects
Some people in each group had side effects during or after their operation. More people who had open surgery had side effects while they were in hospital:

  • 81 people (33%) who had VATS
  • 113 people (44%) who had open surgery

Some of these were not serious or didn’t last long. But some people had more serious side effects. This was just under 1 in 10 people (8%) in each group.

The most common side effects were:

  • infection, which affected more people who had open surgery
  • irregular heart beat (arrythmia), which affected the same number of people in each group
  • air leaking from the lungs, which affected more people who had VATS

A total of 6 people in the VATS group had bleeding problems during the operation. This is compared to one person who had open surgery.

How well the treatment worked
The trial team looked at how many people’s cancer had started to grow again, a year after joining the trial. They found it was low and similar in each group.

They also looked at how many people had died a year after joining the trial. This was also low in both groups, but slightly higher in those who had open surgery:

  • 13 people (6%) who had VATS
  • 18 people (8%) who had open surgery

The 2 main reasons people died were the cancer getting worse and a lung infection called pneumonia. 

It wasn’t possible to say whether there is any difference in how well people do long term. 

The trial team concluded that:

  • video assisted thoracoscopic surgery (VATS) caused less pain and fewer complications than open surgery
  • people who had VATS had a better overall quality of life
  • VATS is cost effective

They suggest that surgeons should use VATS to treat early stage lung cancer when possible.

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

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

Video-Assisted Thoracoscopic or Open Lobectomy in Early-Stage Lung Cancer
E Lim and others
New England Journal of Medicine Evidence, 2022. Volume 1, number 3.

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 we list 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

Professor Eric Lim

Supported by

National Institute for Health Research
Royal Brompton and Harefield NHS Foundation Trust
University of Bristol

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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