New discovery: bone scans can show which men with advanced prostate cancer may benefit from radiotherapy.

Perseverant researchers use Prostate Cancer UK funding to study thousands of scans - turning an unsuccessful trial into one that can improve treatments, with equipment that’s already in hospitals everywhere.

Precision medicine is all about finding the right treatment for the right man at the right time. Usually it involves using recently developed genetic blood tests to understand what makes each man’s cancer tick. But it can also mean using existing techniques in a new way to inform treatment decisions. With support from your donations and our partnership with Movember, scientists have been able to turn a ‘negative’ clinical trial result into a success that will benefit thousands of men.

In 2014, we launched the Belfast-Manchester Centre of Excellence with our partner Movember to bring together world-class expertise in radiotherapy and prostate cancer biology. Radiotherapy is a common treatment for localised prostate cancer, (where the cancer is still in the prostate). The prostate is carefully targeted by a high-energy beam of X-rays which kills the cancer cells.

However, thousands of men are diagnosed with advanced prostate cancer, where the cancer has already spread from the prostate to other parts of the body. At this stage, it’s usually incurable. We desperately need better treatments for these men to stop prostate cancer killing them.

A new precision treatment, or shutting the stable door after the horse has bolted?

For years, researchers have been trying to find out whether radiotherapy targeted at the prostate could still benefit men, even after the cancer had spread elsewhere in the body. This may sound like ‘shutting the stable door after the horse has bolted’, but the researchers suspected this could slow the cancer’s growth.

From 2013 to 2016, this treatment was tested along with several other treatment options for men newly diagnosed with advanced prostate cancer, as part of a trial called STAMPEDE. Disappointingly, the radiotherapy did not appear to make a difference. “When we looked at the results overall, we could see the trial was negative,” says Professor Clarke, one of the researchers involved. But Professor Clarke and his team had some aces up their sleeve and decided to investigate further.

As part of the Centre of Excellence, researchers from the Christie Hospital in Manchester had been collecting detailed information about the men taking part in the trial. In particular, they had gathered images of bone scans and CT Scans. Prostate cancer cells often travel to the bones, so these scans are a common way to monitor the spread of the disease. Professor Clarke and his team suspected that studying these scans in depth may reveal clues about which men could benefit from the radiotherapy.

7,000 scans and one big question.

To find out if they were right, the team had a mammoth task on their hands. They had to trace the scans from the 140 hospitals taking part in the trial, categorise them, document the findings, get independent checks and combine them into a database. “It sounds simple, but actually, it really isn’t,” says Professor Clarke. “The dataset we now have is one of the biggest in the world. We have something like 7,000 scans on our database.”

And rather than simply categorising men into whether the cancer had spread to the bone or not, the team monitored how many tumours they could identify and where exactly the cancer had spread.

“What the study did was to look at the distribution of those cancerous deposits, count them, look at the size of them and combine that information with other features. That gave this study its unique nature,” says Professor Clarke.

With this huge dataset, the researchers could extend their analysis of the trial results to see if the extent of men’s cancer affected their response to radiotherapy.

In 2018, when the STAMPEDE team looked at the data from men with a limited number of tumours growing in the bone, they benefited from radiotherapy targeting the prostate, slowing the cancer’s growth significantly. This benefit was not seen in men whose disease in bone was more extensive.

“The results mean we can predict a positive response to this treatment based on a simple test – a bone scan – which every hospital in the country is using,” says Professor Clarke.

A third of men with advanced cancer could benefit from this treatment, thanks to you.

The final step was to make sure this finding was statistically robust. That’s where another group of researchers, led by Professor Jayne Tierney at UCL, came in. Through a project funded by Prostate Cancer UK, they combined Professor Clarke’s results with those from another large European trial. Their detailed analysis proved the finding from Professor Clarke was indeed correct, and added enough confidence in those results for the guidelines for prostate cancer treatment in the UK, Europe and the US to be changed. Now, men with ‘low volume’ advanced prostate cancer can be offered radiotherapy.

“It’s thanks to your support that we’re able to fund world-class researchers like Professor Clarke and his team, who make the most of data from ongoing trials” says our Director Of Research, Dr. Matt Hobbs, “this ground-breaking achievement could help extend the lives of 25-30% of the men who have advanced prostate cancer when they are first diagnosed, giving thousands of men every year more time with those they love."

Professor Clarke added, “It’s a special feeling when your team discover something new that makes a difference. Thousands of patients around the world now have treatment which benefits them, which they would otherwise not have had. It’s fantastic, and it really does make our research teams and cancer carers feel very good.”

Thank you for supporting Prostate Cancer UK and Movember to make improvements in treatment possible. Donate now to keep momentum, and help stop prostate cancer limiting lives.