Can targeted radiotherapy help men whose cancer comes back after surgery? (PACE Post-Op trial)

Grant information

Reference: MA-TIA25-003
Researchers and Institutions:
Professor Emma Hall, The Institute of Cancer Research, London
Professor Nicholas Van As, The Royal Marsden NHS Foundation Trust
Dr Yae-eun Suh, The Royal Marsden NHS Foundation Trust
Dr Matthew Fittall, University College London
Award: £1,999,833

What you need to know

• When some men have surgery for prostate cancer, a small number of cancer cells can be left behind and begin growing again. These men then have to undergo weeks of daily radiotherapy to get rid of the cancer fully.

• This study will test a much shorter and more precise form of radiotherapy, given in just five treatments, to see if it works as well without worsening the side effects.

• If successful, it could make treatment quicker and easier for men while easing pressure on NHS services – meaning more men would be able to access it.

Why are we funding this research?

For men whose prostate cancer is still in and around the prostate (localised or locally advanced prostate cancer), one of the most common treatments is surgery to remove the prostate and the cancer along with it.

Unfortunately, between 16% and 46% of men who have this surgery later show signs (such as a rising PSA level) that their cancer is growing again – which can mean that a small number of cancer cells were left behind after surgery.

Normally, these men then need to undergo between four and six weeks of daily radiotherapy to treat those leftover cells and fully cure the disease. This is a big burden, taking these men away from their daily lives, and costing them time and money travelling to hospital.

This trial will look at a different, more precise form of radiotherapy that can be given in as few as five visits over a week and a half, to see if it could be used instead – making it much easier for men to manage, while reducing the impact on the NHS.

Although we’ve funded several other projects looking at the potential of this type of targeted radiotherapy, including for reducing the risk of cancer spreading in men with localised disease, and for keeping treatments working longer in men whose cancer has already spread, so far no research has compared it to standard radiotherapy in this group of men. Without that research, the treatment can't be offered routinely to men. 

What will the researchers do?

This trial, called PACE Post-Op, will look at a type of radiotherapy called stereotactic body radiotherapy (or SBRT), and whether it’s as good at getting rid of these remaining cancer cells as traditional radiotherapy.

Like traditional radiotherapy, SBRT kills cancer cells by focusing high-energy x-rays at the cells from outside the body. However, SBRT is an advanced type of radiotherapy that uses multiple, very precise beams of x-rays that cross over at exactly the right point inside the body. The effect is like shining multiple torches at the same point on a wall – the target area gets a high dose of radiation, while the surrounding, healthy area gets much less.

This means the treatment can be done in much fewer visits, because the radiotherapy can be delivered in larger doses to the cancer without causing more damage and worsening the side effects of the treatment. 

The researchers will recruit more than 1,200 men who’ve had their prostates removed but are showing signs that their cancer wasn’t fully removed and is growing again. These men will be split into two groups at random – one group will get the standard type of radiotherapy to the area where their prostate was, and the other will get SBRT.

The team will then follow up on these men for up to 10 years, looking at how well the treatments worked at getting rid of the cancer, how well the men were able to withstand the treatments, how bad any side effects were during and after radiotherapy, and how much the treatments affected the men’s quality of life overall. They’ll also look at the cost of both types of radiotherapy to the NHS.

By comparing these factors across the two groups of men, the researchers will assess whether SBRT is as good as traditional radiotherapy for these men. 

How will this benefit men?

Although multiple research studies have shown that SBRT is safe and effective, so far no studies have compared it directly with traditional radiotherapy for men whose cancer is growing again after surgery. This trial is a crucial step towards making it available to these men.

If successful, the research could give these men a much more convenient way to treat their prostate cancer than the standard four- or six-week course of radiotherapy, reducing the impact on their time and wellbeing, and making the treatment easier to manage.

The shorter course of SBRT would also mean that more men could be treated in the same amount of time, helping more men to access the treatment they need, and reducing the burden on the NHS.