Published: 22 August 2023
A new study has found magnetic resonance imaging (MRI) scans used as a screening test improve prostate cancer diagnosis.
The REIMAGINE study used MRI scans with prostate specific antigen (PSA) density to assess the need for further standard NHS tests.
Results found cancers which would have been missed by a blood test alone. Of 48 participants found to have serious prostate cancer, 50% had a ‘low’ PSA score. Under the current system they wouldn’t be referred for further investigation.
The study was funded by the Medical Research Council and Cancer Research UK. It used findings from Professor Caroline Moore's NIHR Research Professorship work. It was also supported by the University College London (UCL), University College London Hospitals (UCLH) and King’s College London.
MRI could reduce prostate cancer mortality and overtreatment
Researchers invited men aged 50 to 75 to have a screening MRI and PSA test.
Currently, men over 50 in the UK can ask for a PSA test if they are experiencing symptoms or are concerned about prostate cancer. Previous screening studies have used a PSA level of 3ng/ml or above as the benchmark for performing additional tests to look for prostate cancer, such as a biopsy.
Of 303 men who completed both tests:
- 48 (16%) had a positive screening MRI that indicated cancer
- Two thirds had lower PSA levels than the current screening benchmark. They would not be referred for further investigation by the PSA test currently in use
- 29 men (9.6%) were diagnosed with cancer that required treatment
- 3 men (1%) were diagnosed with low-risk cancer that did not require treatment
Professor Caroline Moore (UCL Surgical & Interventional Science and consultant surgeon at UCLH), chief investigator of the study and NIHR Research Professor, said: “The thought that half the men with clinically significant cancer had a PSA less than 3 ng/ml and would have been reassured that they didn’t have cancer by a PSA test alone is a sobering one and reiterates the need to consider a new approach to prostate cancer screening.
"Our results give an early indication that MRI could offer a more reliable method of detecting potentially serious cancers early, with the added benefit that less than 1 per cent of participants were ‘over-diagnosed’ with low-risk disease. More studies in larger groups are needed to assess this further.”
Recruitment found black men were 5 times less likely to respond to the screening invitation than white men. Authors say this will need to be addressed in future research.
Further prostate cancer trials underway
The next step towards a national prostate cancer screening programme is underway. The LIMIT trial is being conducted with a larger number of participants. It will attempt to recruit more black men. This includes through mobile ‘scan in a van’ initiatives. They are designed to visit communities less likely to come forward for testing.
If LIMIT is successful, a national-level trial would be required before prostate cancer screening becomes standard clinical practice.
Professor Mark Emberton, UCL Cancer Institute and consultant urologist at UCLH, and senior author of the study, said: “The UK prostate cancer mortality rate is twice as high as in countries like the US or Spain because our levels of testing are much lower than other countries.
"Given how treatable prostate cancer is when caught early, I’m confident that a national screening programme will reduce the UK’s prostate cancer mortality rate significantly. There is a lot of work to be done to get us to that point, but I believe this will be possible within the next 5 to 10 years.”