Prostate MRI scans could help some men avoid invasive biopsy

More than a quarter of men with suspected prostate cancer could avoid invasive biopsies if they’re offered an MRI scan first, a new international study suggests.

Men with suspected prostate cancer are normally offered an ultrasound-guided biopsy (also called a TRUS biopsy), which involves taking small samples of tissue from the prostate and analysing them for cancer.

But scientists found that having an MRI scan first could help to identify men who don’t need this invasive test.

The study was published in the New England Journal of Medicine and presented at the European Association of Urology conference in Copenhagen.

What did the study show?

The trial involved 500 men who had an abnormal result from a blood test (called the PSA test) or rectal exam. These abnormal results can be a sign of prostate cancer. 

• Half the men were given a standard biopsy 
• The other half had an MRI scan, followed by a targeted biopsy if the scan showed an abnormality. Targeted biopsies are guided by the scan results, which means that fewer samples are needed.

Scientists found that around 1 in 4 men who had an MRI scan didn’t need a biopsy, as the scan showed no abnormalities. And in the men who did need a biopsy, the MRI scan could help guide the test and reduce the number of samples taken.

“We found that patients who had MRI had fewer side effects than those who just had the standard TRUS biopsy,” said Dr Veeru Kasivisvanathan, from University College London, who led the study. The MRI scan is better at indicating which area of the prostate needs to be investigated “so you don’t need to randomly sample the whole prostate”, he added. This means fewer biopsy samples are needed for diagnosis.

Professor Malcolm Mason, Cancer Research UK’s prostate cancer expert, said the research “chimes with the results of the UK PROMIS study”, which also highlighted the potential of MRI scans in prostate cancer diagnosis.

The PROMIS study, which involved 576 men, also found that MRI scans could reduce the number of men needing a standard biopsy by one quarter.

Improving prostate cancer diagnosis

There are several tests that can be used to diagnose prostate cancer. For men with symptoms of prostate cancer, initial tests include the PSA test and rectal exams. If these tests are abnormal, men are typically referred for a biopsy.

“Research has shown that PSA tests alone diagnose a lot of cancers that don’t need treatment,” said Mason. “We need more than just PSA, and MRI could help to distinguish who needs further tests and treatment, and who doesn’t.

“There’s work to be done now to improve the availability of this type of MRI and standardise the way it’s used.”