A new MRI-based prostate cancer test has been shown to be almost twice as likely to identify the disease – and less likely to incorrectly diagnose it – than the current standard technique.
The findings came from the Prostate MR Imaging Study (PROMIS) – a trial investigating the use of multi-parametric magnetic resonance imaging (MP-MRI) as a triage test compared to the current standard prostate screening method of transrectal ultrasound (TRUS).
MP-MRI combines four different types of images of the prostate giving doctors a much more detailed and clearer image of the organ than TRUS.
Traditional TRUS biopsies use ultrasound imaging of the prostate as a guide for where to take samples of the prostate from. Unlike the structure detail and distinct differences in tissues that can be revealed through and MRI, an ultrasound scan produces a black and white representation of tissues and organs.
As TRUS produces far less specific structures than MRI, using the current method to find cancerous tumours in the prostate is very much a shot in the dark. As a result, many men undergo unnecessary biopsies, have cancers missed by TRUS, and often experience side effects from the invasive nature of the technique, including infection and erectile dysfunction.
In this study, MP-MRI was found to be more sensitive (93%) at detecting prostate cancers than TRUS (48%) as well as having the potential to lower unnecessary biopsies by around 25%.
“MP-MRI, used as a triage test before first prostate biopsy, could reduce unnecessary biopsies by a quarter,” state the study authors in the paper. “MP-MRI can also reduce over-diagnosis of clinically insignificant prostate cancer and improve detection of clinically significant cancer.”
Although the results suggest MP-MRI to be a far better option for pre-biopsy screening than TRUS, the reality of it becoming the go-to technology for prostate screening relies heavily on funding. At present, MRI scanning is available in few UK hospitals meaning – according to Prostate Cancer UK – only one third of men in the country would be able to benefit from MP-MRI prostate screening prior to biopsy.
Responding to the study’s findings, Prostate Cancer UK chief executive Angela Culhane said: “This is the biggest leap forward in prostate cancer diagnosis in decades with the potential to save many lives, so it’s critical that urgent action is taken to make it available to men.
“However, this complex technique can only become a routine part of the diagnostic pathway once it can be guaranteed it can be rolled out safely and in a way that produces the best outcomes for men. We are committed to doing everything we can to make this happen.”
UK cost-effectiveness body, the National Institute for Health and Clinical Excellence (NICE), is currently reviewing the possibility of offering the technique.