A trial comparing surgery, conventional radiotherapy and stereotactic radiotherapy for localised prostate cancer (PACE)

Trial design
This trial was for men with prostate cancer that was contained within the prostate and had not spread. 

Everyone taking part was put into a risk group. This was based on how likely it was that their cancer would grow or spread. They were then put into one of two treatment groups at random.

There were 3 parts to this trial.

PACE A was for men with low or medium risk cancer. The doctors thought that surgery was a good treatment option for them. They either had surgery or stereotactic radiotherapy.

PACE B was also for men with low or medium risk cancer. But their doctors didn’t think surgery was a good treatment option for them. They either had conventional radiotherapy or stereotactic radiotherapy.

PACE C was for men with medium or high risk cancer. Surgery was not a good treatment option for them. They had either conventional radiotherapy or stereotactic radiotherapy.

PACE trial randomisation diagram

In 2022, the research team published some results about the long term side effects for people in PACE B.

They plan to publish more results in the future. This will include information about the men in PACE A and PACE C. 

This is a summary of the results so far.

Results
The 874 people who joined PACE B were put into a treatment group at random. Half had standard radiotherapy, and half had stereotactic body radiotherapy (SBRT).

The research team looked at how many people had moderate or more severe side effects, 2 years after treatment. It was low, and similar in both groups.

The number of people who had moderate or more severe side effects that affected their bowel was:

• 11 people (3%) who had standard radiotherapy
• 6 people (2%) who had stereotactic radiotherapy 

And the number of people who had moderate or more severe side effects that affected their bladder was:

• 8 people (2%) who had standard radiotherapy
• 13 people (3%) who had stereotactic radiotherapy

The research team first looked at the side effects people were having in 2019. They looked at short term side effects, 3 months after treatment. 

They found that between about 1 in 10 people (10%) and 3 in 10 people (27%) were having bowel or bladder side effects at that time. A few more people who had standard radiotherapy had these side effects. There is more information about this in the link below.

We have more information about the side effects of prostate radiotherapy in our Prostate cancer section.

Conclusion
The research team concluded that stereotactic radiotherapy did not cause more long term side effects than standard radiotherapy 2 years after treatment.

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

Please note, these articles are not in plain English. They have been written for health care professionals and researchers.

Intensity-modulated fractionated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): acute toxicity findings from an international, randomised, open-label, phase 3, non-inferiority trial
D Brand and others
The Lancet Oncology, 2019. Volume 20, Issue 11. Pages 1531-1543.

Intensity-modulated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): 2-year toxicity results from an open-label, randomised, phase 3, non-inferiority trial
A Tree and others
The Lancet Oncology, 2022. Volume 23, Issue 10. Pages 1308-1320

Where this information comes from    
We have based this summary on the information in the articles above. They have been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves.