A trial of robotic assisted keyhole surgery for cancer of the rectum (ROLARR)

Cancer type:

Bowel (colorectal) cancer
Rectal cancer




Phase 3

This trial looked at robotic assisted surgery to remove rectal cancer. Rectal cancer is cancer of the back passage (rectum Open a glossary item).

More about this trial

The usual first treatment for rectal cancer is surgery. In the past, surgeons removed most rectal cancers by making a large cut in the tummy (abdomen). This is called open surgery. But more recently, they have developed keyhole surgery to remove cancers from the bowel. This type of operation is called a laparoscopic resection.
They use a long camera called a laparoscope, which is passed into the abdomen through a small cut. Other small cuts allow long instruments to enter the abdomen to perform the operation. We know from earlier research that keyhole surgery is as good as open surgery for removing bowel cancers.
But sometimes, when a surgeon starts an operation using keyhole surgery, they may need to switch to open surgery. This happens more frequently for rectal cancer because it is a difficult operation.
In this trial, surgeons looked at a system called robotic assisted keyhole surgery. The surgeon sits at a control unit a few feet away from the patient. They control the movement of a set of robotic surgical instruments, guided by a video camera.
The trial compared having robotic assisted keyhole surgery with keyhole surgery. 
The main aims of the trial were to find out if robotic assisted keyhole surgery 
could reduce:
  • the number of times surgeons needed to switch to an open operation
  • complications during and after surgery
  • the length of time people stayed in hospital

Summary of results

The trial team found that having robotic assisted surgery did not reduce the risk of needing open surgery for rectal cancer. There was no difference between robotic assisted surgery and key hole surgery in terms of treating rectal cancer. 
The researchers published the results in 2017. This trial took place worldwide. It was a phase 3 trial
466 people joined the trial and had surgery. People were put into 1 of 2 treatment groups at random.
  • 236 had keyhole surgery as their planned surgery 
  • 230 had robotic surgery as their planned surgery 


40 surgeons took part in the trial. They had varying levels of experience with robotic assisted surgery. 
The researchers looked at the how many times the surgeons switched from the planned surgery to open surgery. 
This happened in: 
  • 28 people out of 236 who had keyhole surgery
  • 19 people out of 230 who had robotic assisted surgery
These numbers are different, but the researchers say the difference between the 2 groups is not statistically significant. This means it could have happened by chance. 
They also looked at:
  • length of hospital stay 
  • quality of life Open a glossary item 
They found no difference in either of these between the 2 groups. 
Side effects
The researchers looked at complications people had during surgery, for example having a bleed. And after surgery, for example:
  • infections 
  • diarrhoea or constipation 
  • bladder problems
They didn’t find a difference in complication rates between those who had robotic assisted surgery and those who had keyhole surgery. 
Costs of surgery
The researchers looked at the cost of robotic assisted and key hole surgery. Robotic assisted surgery was on average £1,000 more expensive because the operations took longer and the robotic instruments were more expensive.
The trial team concluded that in this trial, having robotic assisted surgery did not reduce the risk of having open surgery for rectal cancer. 
But researchers say there were some limitations to this conclusion. The surgeons had varying levels of experience with robotic assisted surgery. Most were very well trained to do keyhole surgery but some were still learning the robotic surgery technique. 
So, the researchers suggest that there is no advantage to having robotic surgery when the surgeons have different levels of experience with the technique. 
This trial has increased knowledge about what works and what doesn’t for rectal cancer. 
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

Professor David Jayne

Supported by

Medical Research Council (MRC)
NIHR Clinical Research Network: Cancer
NIHR Efficacy and Mechanism Evaluation (EME) Programme
University of Leeds

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.

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