MRI scans could 'change the equation' for prostate cancer screening
MRI scans could "change the equation" for prostate cancer screening and potentially fulfil a similar role as mammograms, research suggests.
A study found that magnetic resonance imaging (MRI) halved the number of men wrongly identified as needing radical treatment.
It also cut the number of unnecessary biopsies - surgical procedures that remove tissue samples for analysis - by 70%.
MRI could conceivably form the basis of national screening programmes for prostate cancer with men having routine examinations in much the same way as women undergo mammograms, said researchers.
Lead scientist Dr Arnout Alberts, from Erasmus Medical Centre in Rotterdam in the Netherlands, said: "Now we have shown that MRI screening has potential, we need confirmatory studies in a true screening setting to allow us to get a better handle on the statistics and costs.
"MRI screening for prostate cancer will be more expensive than the currently used approach, but introducing mammography screening a generation ago was also expensive. We have to decide if it's worthwhile.
"In this study we achieved a 70% reduction in biopsies and a 50% reduction in over-diagnosis of insignificant prostate cancer. If larger studies can reproduce these results it will mean a considerable saving further down the line."
Each year around 46,700 new cases of prostate cancer are diagnosed in the UK and more than 11,000 men die from the disease.
But doubts about the outcomes of diagnostic procedures have meant that a national prostate cancer screening programme has never been introduced in the UK.
Currently all prostate cancer diagnosis starts off by measuring a blood marker called PSA (prostate specific antigen).
If PSA levels are high, the patient is asked to have a biopsy. However both PSA tests and biopsies can throw up inaccurate or misleading results.
PSA can be raised when a man is cancer-free or look normal when he has a tumour.
Biopsies, carried out by removing core tissue samples with fine needles, can miss a tumour or flag up small slow-growing cancers that do not pose a serious threat.
As a result, some prostate cancers may escape detection while in other cases men end up having unnecessary surgery or radiotherapy that causes serious side effects such as impotence.
The new research shows that an MRI scan conducted before any biopsies are taken provides a more reliable system of diagnosis that could form the basis of screening.
Dr Alberts said: "This could change the balance of the equation."
The research, from an investigation called the European Randomised study for the Screening of Prostate Cancer (ERSPC), was presented at the European Association of Urology's annual conference in London.
The Dutch team compared outcomes of biopsy-only and MRI-targeted screening in a group of more than 300 men who had all previously been tested and shown to have raised PSA.
Biopsies alone or guided by MRI had a similar detection rate for dangerous high-grade cancers.
Heather Blake, from the charity Prostate Cancer UK, said: "Using (MRI) for first line screening is an exciting possibility but, as the authors acknowledge, has significant issues around cost and resource use.
"We therefore need a test to establish which men should receive an mpMRI (multi-parametric MRI) scan. Current suitability is based on the results of a PSA blood test - a test which is riddled with complexities."