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Robotic rectal cancer surgery does not appear technically easier than standard keyhole surgery. The researchers, in this trial, judged this by measuring the need to ‘convert’ a keyhole procedure to open surgery when operating. This NIHR-funded trial also found that robotic surgery produced similar clinical results to standard laparoscopic (keyhole) surgery in treating rectal cancer.

In the trial, 28 out of 230 patients (12%) who received keyhole surgery were converted to open surgery, compared with 19 out of 236 (8%) who received robotic surgery. This difference did not achieve statistical significance. There were also no differences in the likelihood of removing the whole tumour, surgery-related complications and bladder or sexual function. Longer-term outcomes such as three-year recurrence and overall survival were also similar.

These results suggest robotic rectal surgery, which costs £1,000 more than laparoscopic surgery due to ongoing equipment costs and longer operating time, may not be cost-effective.

Why was this study needed?

There were 9,614 cases of rectal cancer in England in 2017. It is more common in older people, with most cases occurring after the age of 60. Data between 2013 and 2017 shows more than 80% survive for at least one year after diagnosis and 60% survive for at least five years.

Surgery is the most common treatment for rectal cancer and a number of techniques may be used. Open surgery requires the surgeon to make a large cut in the abdomen and sometimes the perineum to access the rectum. Keyhole or laparoscopic surgery, where the surgeon makes a number of small incisions to insert instruments guided by a camera, can avoid the need for open surgery and reduce recovery time.

Robot-assisted surgery, where the surgeon guides a robot to perform laparoscopic surgery, was introduced as a potential solution to some of the technical difficulties of the keyhole approach in the pelvis. However, the evidence is limited. This trial aimed to address that knowledge gap.

What did this study do?

The ROLARR trial compared robotic-assisted surgery with laparoscopic surgery for rectal cancer resection by looking at the number of operations which had to be converted to open surgery. Single centre studies had shown some advantage of robotic over laparoscopic surgery in terms of lower conversion rates, and suggested improved post-operative bladder and sexual function in the robotic-assisted arm.

However, the main disadvantage of robotic, compared with laparoscopic, surgery is the increased hospital costs. The authors, therefore, selected the main outcome as one that measures the ease of operating (the conversion rates) as well as looking at clinical operative outcomes including having clear margins, and later clinical outcomes such as recurrence.

This was a multicentre randomised trial conducted in ten developed countries, including the UK, during 2014 and 2015. A total of 466 patients underwent surgery: 236 via laparoscopic and 230 via robotic-assisted techniques. The average age of participants was 65, and 68% were men. Participants were followed-up for up to three years.

The trial had some limitations. There were 40 surgeons involved, with varying degrees of experience, especially with robotic surgery. Some sub-analyses were limited due to small numbers, such as comparing results for obese and very obese patients.

What did it find?

  • There was no significant difference in the rate of conversion to open surgery, at 28/230 (12.2%) in the laparoscopic group and 19/236 (8.1%) in the robotic group (adjusted odds ratio [aOR] 0.6, 95% confidence interval [CI] 0.3 to 1.2).
  • Positive surgical margins (cancer cells at the edge of the surgically removed tissue) occurred in a similar proportion, at 14/224 (6.3%) of the laparoscopic group compared with 12/235 (5.1%) of the robotic group (aOR 0.8, 95% CI 0.4 to 1.8).
  • There was no significant difference in post-operative complications within 30 days, occurring in 73/230 (31.7%) after laparoscopic surgery compared with 78/236 (33.1%) after robotic surgery (aOR 1.0, 95% CI 0.7 to 1.6). Post-operative complications between 30 days and six months after the operation were also similar, 38/230 (16.5%) after laparoscopic surgery compared with 34/236 (14.4%) after robotic surgery (aOR 0.7, 95% CI 0.4 to 1.3).
  • Other measures, including intra-operative complications, bladder function, sexual function, fatigue, physical and mental general health, three-year recurrence, disease-free survival and overall survival were similar across the groups.
  • The cost of robotic surgery was £980 higher due to the longer duration of surgery and cost of instruments.

What does current guidance say on this issue?

NICE guideline CG131 (2011, updated 2014) recommends that laparoscopic resection is performed as an alternative to open resection for individuals with colorectal (bowel) cancer in whom both laparoscopic and open surgery are considered suitable, but currently does not mention robotic surgery.

This guideline is due to be further updated, and in August 2019 NICE published a draft guideline for consultation. This states that laparoscopic surgery should be offered for rectal cancer, with open surgery being considered where clinically indicated. It says robotic surgery should only be considered within established programmes that have appropriate audited outcomes. The final guideline is due to be published in January 2020.

What are the implications?

Overall, the trial results do not support the extra costs involved in performing surgical resection using robotic-assisted laparoscopy for this indication and in this population group.

Citation and Funding

Jayne D, Pigazzi A, Marshall H et al. Robotic-assisted surgery compared with laparoscopic resection surgery for rectal cancer: the ROLARR RCT. Efficacy and Mechanism Evaluation. 2019;6(10).

This project was funded by the Efficacy and Mechanism Evaluation (EME) programme (project number 08/52/01). Additional funding was provided by the Chief Scientist Office, Scottish Government Health and Social Care Directorate, Health and Care Research Wales and the Health and Social Care Research and Development Division, Public Health Agency in Northern Ireland.


Day A, Tilney H and Gudgeon M. Robotic rectal cancer surgery offers significant benefits over the laparoscopic technique. Gut. 2015;64:A332.

NHS website. Treatment: bowel cancer. London: Department of Health and Social Care; updated 2019.

NICE. Colorectal cancer: diagnosis and management. CG131. London: National Institute for Health and Social Care Excellence; 2014.

Office for National Statistics. Cancer registration statistics, England: 2017. London: Office for National Statistics; April 2019.

Office for National Statistics. Cancer survival in England – adults diagnosed 2013 – 2017. London: Office for National Statistics; August 2019.

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre

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