‘Early warning’ blood test could help men with advanced prostate cancer get the right treatment sooner

Around 10,000 men are diagnosed with advanced prostate cancer every year in the UK. Most are treated with hormone therapy, which can be very effective, but it doesn’t work equally well for everyone – meaning some men will need further treatments like chemotherapy. 

Right now, doctors mainly rely on PSA blood tests to judge whether a treatment is working. But PSA can hang around in the blood for months, meaning it can take a long time to spot when a treatment isn’t doing its job. 

For men whose cancer is aggressive, that delay matters. 

DNA from prostate cancer tumours behaves differently. It disappears from the bloodstream quickly, so if it’s still detectable weeks after treatment starts, it may be a sign that the cancer is continuing to grow. 

That means this test could give men and their doctors a much earlier, clearer signal about whether a treatment plan is right or whether it’s time to switch. 

In PARADIGM, researchers studied blood samples from men with newly diagnosed advanced prostate cancer being treated across the UK. 

They found that around 3 in 10 men still had detectable tumour DNA in their blood after 6–12 weeks of treatment. These men had a much shorter life expectancy than those whose tumour DNA was no longer detectable. 

Combining these results with PSA blood tests found a small group of men who were 20 times more likely to die from their disease than men with undetectable tumour DNA and very low PSA levels.  

These men would likely benefit greatly from earlier, more intensive treatment. 

Crucially, the test doesn’t just have the potential to find men who need more treatment. It could also help spare other men from treatments they don’t need. 

If doctors can be confident early on that a man’s cancer is responding well, they may be able to avoid adding extra drugs that bring serious side effects – helping men live better as well as longer. 

And because tumour DNA responds so quickly, the test could also transform research, allowing new treatments to be tested and improved much faster than is currently possible. 

Dr Hayley Luxton, Head of Research Impact & Engagement at Prostate Cancer UK, said: “Thousands of men are diagnosed with advanced, incurable prostate cancer every year, and right now, we can’t say which treatment will be best for which man until much later on. 

“By showing if treatments are effective so much sooner, this test could not only help men with advanced prostate cancer live longer and better, but could also massively speed up prostate cancer research in future. 

“We’re incredibly proud to have helped fund this research which could make such a difference for men with prostate cancer – both in the clinic, and in the lab.”  

The PARADIGM team is now working to show how this blood test could be used reliably in larger numbers of men by rolling it out in other clinical trials. 

Professor Gerhardt Attard, who led the study at University College London, said: “This is so exciting because it’s the first time we’ve ever seen such a clear link between tumour DNA in the blood and outcomes for men with hormone-sensitive advanced cancer. By using it alongside PSA blood tests, we can personalise treatments and help find the right balance between reducing side effects and giving men more time with their loved ones. 

“The next step is to show that we can reproduce this and how it can be used in practice. That’s why we’re implementing it across all our clinical trials for advanced prostate cancer to get the evidence we need to roll this out as soon as possible.  

“We’re hugely grateful to Prostate Cancer UK and Movember, whose funding made this research possible.” 

Please help us fund more research like this. Your donation helps us fund vital research into better ways to diagnose and treat prostate cancer.