£2m trial will test whether new scan could stop high-risk prostate cancer from spreading
A new kind of scan that could improve the treatment of high-risk prostate cancer compared with the scans currently used will be tested in a new £1.89 million clinical trial led by consultant urological surgeon Professor Hashim Ahmed.
The trial – AVIDITY – is funded by Prostate Cancer UK and will test this innovative scan, called PSMA PET/CT, to look at whether it can improve treatment for the thousands of men diagnosed with high-risk prostate cancer each year.
Imaging to better understand prostate cancer spread
For some men diagnosed with prostate cancer, doctors can tell from their initial biopsy that their cancer is aggressive and more likely to spread outside of their prostate. This is called high-risk prostate cancer. However, the biopsy cannot tell whether spread outside the prostate has happened already or not at the point of diagnosis.
To do this, doctors rely on imaging – taking scans of the whole body to check whether any cancer can be seen in places other than the prostate (usually the bones or the lymph nodes). Accurately detecting if and where high-risk cancers have spread is crucial for deciding which treatment options are best for each man.
Currently, the way high-risk prostate cancers are assessed and treated means some men will have cancer that has spread without being detected, and other men will receive unnecessary treatments, just in case their cancer has spread but has not been detected.
Doctors use two separate imaging tests to check if prostate cancer has spread: a CT scan (which takes detailed pictures of inside the body) and a bone scan (which looks for cancer in the bones). However, the two imaging techniques are known to miss some areas where cancer has spread – especially when there is only a small amount of disease in those locations. That leaves doctors and men with high-risk prostate cancer the choice between treating only the prostate or treating both the prostate and other possible cancer.
In current UK practice, most men receive extra treatment, despite the potentially unnecessary side effects.
New scans can see smaller cancers
Research has already shown that PSMA PET/CT scans can see more, and smaller, cancer that has spread than the current imaging techniques.
Currently, it is unclear if PSMA PET/CT definitively sees all cancer spread and enables more accurate treatment decisions. The AVIDITY trial will test this, following men for longer than previous trials.
Led by Professor Hashim Ahmed from Imperial College London, the trial will recruit men from over 30 centres around the UK. The trial is also being co-led by Mr Martin Connor and Professor Tara Barwick from Imperial College London, as well as Professor Rhian Gabe and Dr Adam Brentnall from Queen Mary University of London.
They will randomly divide the men with high-risk prostate cancer into two groups. One will receive treatment based on what the current standard imaging tests (CT scan and bone scan) show. The other group will receive the treatment based on the findings of the new PSMA PET/CT scan. Up to 1000 men will be recruited for the trial. Both groups will have their cancer treatment decisions made based on the imaging results they receive.
The researchers will follow these men over time, checking in at 24 and 48 months after the first scan to see if there is any cancer spread and if any men have developed metastatic cancer. If the new scan proves more effective, it could become the standard method for staging high-risk prostate cancer and guiding more accurate treatment for men.
Professor Hashim Ahmed, who is leading the trial, said: “We know that the way we currently look for prostate cancer spread in men, using a CT and a bone scan, can miss things. A PSMA PET/CT scan means we can look at everything at once and detect smaller lesions, reducing the risk that we miss some cancer spread.
“Whilst the new PSMA PET/CT scan does show up more areas, we do not yet know whether changing treatment based on the new scan actually makes a difference to survival. AVIDITY will give us the answer.
“Receiving funding from Prostate Cancer UK is allowing us to undertake this crucial work, which could see a change to standard methods of imaging and result in men receiving more personalised treatment plans. We hope that the trial will show us the best way to image high-risk cancers, and if current methods need to change.”
Dr Matthew Hobbs, Director of Research at Prostate Cancer UK, said: “Knowing that your prostate cancer is likely to spread can be deeply unsettling. Men in this situation need certainty that they are going to get the best treatments at the right time based on their actual cancer, as preventing spread is likely to remove the possibility that prostate cancer will become terminal. Unfortunately, the current way we assess high-risk prostate cancers is imperfect, and means some men will have cancer spread that hasn’t been detected, and other men will get treatments they don't need, which can cause challenging side effects.”
“We expect this could be a groundbreaking piece of work, as by combining the best of the CT and bone scans that we use now and following the men on this trial over time, we’ll be able to tell which scanning method is best for controlling cancer spread. This could vastly improve treatments for men with high-risk prostate cancers.
“Prostate cancer is a complex, but common cancer. Over 12,000 men die from prostate cancer every year in the UK. One way we can reduce that number is to fund the research that delivers more accurate diagnosis and more precise treatment. Prostate Cancer UK is the largest funder of that research in the UK, and our Transformational Impact Awards were designed to fund groundbreaking, globally impactful research like this. We are hugely excited to support this trial and to deliver the results that allow men to navigate prostate cancer successfully giving them longer, fuller lives.”
