MRI scans to be trialled as test for prostate cancer

This article was taken from: https://www.theguardian.com/society/2019/jun/09/mri-scans-to-be-trialled-as-test-for-prostate-cancer

By Hannah Devlin Science correspondent

Simple scans ‘could revolutionise the way that we diagnose disease’, says professor

Hundreds of men will be given MRI scans in a groundbreaking clinical trial that scientists say could transform screening for prostate cancer.

The £5m trial, which begins in August, is pioneering a simple, 10-minute scan that scientists hope could provide the first reliable method for identifying dangerous tumours in the general population.

It follows a change in guidelines from the National Institute for Health and Care Excellence (Nice) last month, which made MRI scans the first line test for diagnosis of the disease. Unlike blood tests, the latest generation of scans appear to be effective at distinguishing between cancers that are likely to grow and spread and benign tumours that are safe to leave untreated.

“I think that could revolutionise the way that we diagnose disease and hopefully identify men who would be better treated than not treated,” Prof Mark Emberton, the dean of medical sciences at University College London told Cheltenham Science Festival.

Since prostate cancer grows slowly, it is possible that men with a negative scan at 55 or 60 years might effectively be given the all-clear for many years to come – or even for life. “If your prostate comes back looking very clean … you’re probably very unlikely to develop prostate cancer,” said Emberton. “It may be once we learn a bit more about it that you need to refresh it every 10 years or something like that.”

Currently, screening for prostate cancer is not recommended in the UK because the available tests are too unreliable. For instance, raised levels of the protein PSA in the blood are linked to prostate cancer, but about 75% of men with high levels turn out to not have aggressive cancer that needs treatment and about 15% of men with cancer have normal levels of PSA.

“You end up with a lot of men being diagnosed with cancer that isn’t destined to kill them,” said Emberton. “What’s beautiful about MRI is it overlooks the many, many cancers which don’t need to be diagnosed.”

The failure to detect prostate cancer early makes it difficult to treat and 11,000 men die from the disease in the UK each year.

The latest trial, funded by the Medical Research Council and Cancer Research UK, will invite 1,000 men aged 55 to 75 for scans through two London GP surgeries.

The target is to scan 450, but how willing men will be to take up the offer is an open question. “We think they will,” said Emberton. “One of the reasons people didn’t before is because they were worried about the examination. You know, finger in the bottom. They were worried about the biopsy needle in the prostate. This involves neither.”

The 10-minute scan, which it is estimated will cost about £150, is a simplified version of the 30-minute scan used to diagnose cancer in men who are at risk.

The scientists are assessing the prevalence of prostate tumours in the population. It is anticipated that more than 90% of men should get a clean bill of health, with others being either referred for treatment or monitored over time.

Karen Stalbow, the head of policy, knowledge and impact at Prostate Cancer UK, said the trial could provide an exciting step towards a national screening programme. “If the results are positive, then MRI scanning could offer a non-invasive first stage of prostate cancer diagnosis in the future,” she said.

However, others cautioned that the reliability of MRI had not yet been established in the wider population.

Prof Ros Eeles, professor of prostate cancer genetics at the Institute of Cancer Research in London, said: “The use of MRI of the prostate will be important in general management of prostate cancer assessment. However, currently it is not at all clear that MRI will be reliable to detect all cancers.

“In men at higher genetic risk, there are studies being undertaken at the Institute of Cancer Research to assess if men who have a genetic predisposition to aggressive prostate cancer have changes on their MRI when they get prostate cancer. At present, it is not at all certain that it will be reliable to rely on MRI alone for this assessment.”