MRI scans ‘revolutionise’ prostate cancer diagnosis – UK study
A study by British researchers has found that a 10-minute MRI scan to screen men for prostate cancer was far more accurate at diagnosing the disease than blood tests, which search for high levels of a protein called PSA.
MRI picked up some serious cancers that would have been missed by PSA alone, reports BBC.
At present there is no national screening programme because PSA is considered too unreliable, although men over 50 can request a PSA test.
Prostate cancer usually develops slowly and there may be no signs or symptoms for years. Some people never develop any problems from it, but in others, the cancer can be aggressive and deadly.
For the Reimagine study, which was published in BMJ Oncology, men aged 50 to 75 were invited for screening MRI and PSA tests at University College Hospital, London.
Of the 303 who had both tests, 48 had a positive MRI that indicated cancer and of these, 25 were diagnosed with significant cancer after further tests, including biopsies.
More than half the men whose cancer was picked up on MRI had low PSA test scores below 3ng/ml, which is considered normal, and so would have been falsely reassured they were free of disease.
Prof Caroline Moore, consultant urologist UCLH and chief investigator of the study at University College London, said: “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% of participants were ‘over-diagnosed’ with low-risk disease.”
For the Reimagine trial, black men were five times less likely to come forward for screening than white men, even though they have a higher risk of prostate cancer.
Saran Green, another study author from King’s College London, said: “One in four black men will get prostate cancer during their lifetime, which is double the number of men from other ethnicities. Given this elevated risk, it will be crucial that any national screening programme includes strategies to reach black men and encourage more of them to come forward for testing.”
Professor Mark Emberton, senior author of the study, said a screening programme could be up and running within the next decade: “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. Given how treatable prostate cancer is when caught early, a national screening programme could reduce the UK’s prostate cancer mortality rate significantly.”
Simon Grieveson, assistant director of research at Prostate Cancer UK, said: “When a man’s prostate cancer is caught early, it’s very treatable. Sadly, more than 10 000 men each year are diagnosed too late, when their cancer has already spread.
“MRI scans have revolutionised how we diagnose prostate cancer… These results are extremely exciting, and we now want to see much larger, UK-wide studies to understand if using MRI as the first step in getting tested could form the basis of a national screening programme.”
Prevalence of MRI lesions in men responding to a GP-led invitation for a prostate health check: a prospective cohort study
Caroline Moore, Elena Frangou, Neil McCartan, Mark Emberton, et al.
Published in BMJ Oncology Volume 2 Issue 1
In men with a raised prostate-specific antigen (PSA), MRI increases the detection of clinically significant cancer and reduces over-diagnosis, with fewer biopsies. MRI as a screening tool has not been assessed independently of PSA in a formal screening study. We report a systematic community-based assessment of the prevalence of prostate MRI lesions in an age-selected population.
Methods and analysis
Men aged 50–75 were identified from participating general practice (GP) practices and randomly selected for invitation to a screening MRI and PSA. Men with a positive MRI or a raised PSA density (≥0.12 ng/mL2) were recommended for standard National Health Service (NHS) prostate cancer assessment.
Eight GP practices sent invitations to 2096 men. 457 men (22%) responded and 303 completed both screening tests. Older white men were most likely to respond to the invitation, with black men having 20% of the acceptance rate of white men.
One in six men (48/303 men, 16%) had a positive screening MRI, and an additional 1 in 20 men (16/303, 5%) had a raised PSA density alone. After NHS assessment, 29 men (9.6%) were diagnosed with clinically significant cancer and 3 men (1%) with clinically insignificant cancer.
Two in three men with a positive MRI, and more than half of men with clinically significant disease had a PSA <3 ng/mL.
Prostate MRI may have value in screening independently of PSA. These data will allow modelling of the use of MRI as a primary screening tool to inform larger prostate cancer screening studies.