MRI scan more accurate than blood test at diagnosing prostate cancer, UK study finds

A 10-minute MRI scan is a much more accurate way of diagnosing prostate cancer than the blood test used widely at present and could form the basis of a screening programme, according to a study published by UK scientists on Tuesday.

Researchers at University College London gave both an MRI scan and PSA test to 303 men aged 50 to 75. The scan showed signs of cancer in the prostate of 48 men, although 32 of them had less PSA in their blood than the level of 3 nanograms per millilitre (ng/ml) currently recommended for further investigation.

Clinical assessment then found that 29 men had tumours that needed treatment, and that 15 of them serious cancer but a PSA reading below 3ng/ml, according to the study published in BMJ Oncology.

“The thought that over 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,” said Caroline Moore, professor of surgery at UCL and the study’s chief investigator.

“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,” she added.

Prostate cancer is the most common tumour in men, with about 52,000 new cases every year in the UK, according to charity Cancer Research UK. It is responsible for 12,000 deaths a year.

At present, men over 50 in the UK can request a blood test for PSA if they are concerned about prostate cancer but there is no screening programme. The protein tends to be raised in men with prostate cancer but high levels often have other causes; levels can sometimes remain low even though a prostate tumour is present.

The next stage in assessing the feasibility of a national prostate screening programme will be a larger MRI-based study, also led by UCL. The project will recruit 800 men from hospitals in London, Cambridge and Manchester and a community site in London. It aims to use a new technique capable of detecting prostate cancer in a five-minute scan that could be delivered using a mobile MRI scanner located in a travelling van.

Mark Emberton, professor of oncology at UCL, said: “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 five to 10 years.”