New radiotherapy trial aims to keep treatment working longer for men with advanced prostate cancer

Men with advanced prostate cancer could soon see their treatments work for longer, protecting their quality of life, thanks to a new clinical trial made possible by you. 

We're funding a team at The Institute of Cancer Research and The Royal Marsden to test whether a highly targeted form of radiotherapy can keep existing treatments working for longer, giving men more time before they need to move on to tougher options like chemotherapy. 

The idea builds directly on the results of an earlier study we funded called TRAP, which showed that targeted radiotherapy could slow the growth of advanced prostate cancer for some men, even when their cancer had begun to stop responding to hormone therapy.  

The new trial, called STAR-TRAP, aims to confirm these groundbreaking results in a much larger group of men and, if it’s successful, could revolutionise the way we treat advanced prostate cancer. 

In the original TRAP trial, led by Dr Alison Tree at The Royal Marsden, men with advanced cancer were given a type of radiotherapy called stereotactic body radiotherapy (or SBRT) after their cancer had begun to grow again.  

Normally, the cancer beginning to grow and spread again would be taken as a sign that the cancer has become resistant to the treatment, and that the man should start chemotherapy. 

However, the team behind TRAP and STAR-TRAP believes that for some men, only some tumours have stopped responding to treatment and, if we treat those cells with targeted radiotherapy, the rest of the cancer will still respond to hormone therapy. 

The results from TRAP bear this out. Men typically had an extra six months before their cancer started to progress again, and more than 40% of the men saw no progression at all after a year.  

For men running out of treatment options, that extra time without chemotherapy – and without the side effects that come with it – can make a huge difference. 

Now, STAR‑TRAP will put this idea to the test in a much larger way. 

Led by Dr Julia Murray at The Royal Marsden and Professor Emma Hall at The Institute of Cancer Research, the study will recruit 236 men with advanced prostate cancer. 

Three‑quarters of the men will be responding well to treatment, while the remaining quarter will have signs that their hormone therapy is starting to become less effective. 

Half the men will continue with their usual treatment. The other half will receive SBRT on top of it.  

SBRT delivers very precise, intense bursts of radiation to tumours using multiple beams that cross over at exactly the right point. The tumour gets a high dose, while the surrounding tissue gets much less – making side effects less likely.  

By comparing these two groups, the researchers hope to discover whether SBRT can reliably delay the men’s cancer from progressing and, in turn, delay the need for next‑line treatments.  

They’ll also analyse the men's scans – both MRI and advanced PSMA PET‑CT scans – to explore whether there are ways to predict which men are most likely to benefit from adding SBRT to their treatments.  

If the trial is successful, STAR‑TRAP could change how we treat advanced prostate cancer across the UK. It could mean that instead of switching treatments as soon as the cancer starts to stir again, men might be able to 'reset the clock' using brief bursts of targeted radiotherapy. That could help them live longer, stay well for longer, and hold off the side effects of later treatments. 

Dr Julia Murray, Consultant Clinical Oncologist at The Royal Marsden, said: “STAR-TRAP will enable us to see if targeted radiotherapy can delay the next line of treatment for men with metastatic prostate cancer. By delaying the progression of cancer or the next treatment, we could help men enjoy a better quality of life for longer.” 

Simon Grieveson, our Assistant Director of Research, said: “The exciting results from TRAP suggested that targeting radiotherapy to the sites where the cancer has spread can delay further progression of the disease and the need for subsequent treatments, such as chemotherapy. 

“STAR-TRAP will now test this at a much greater scale and the results of this trial, if successful, could benefit thousands of men in the UK each year.” 

If you’re interested in taking part in this trial, this page has more information about who can join and what the trial will involve. If you’d like support with deciding whether taking part in a clinical trial is right for you, you can speak to your medical team or contact our Specialist Nurses on 0800 074 8383 for general information and support.