He notes that the role of MRI as an adjunct to prostate cancer is well established through randomized trials and prospective series. But, until now, MRI testing has always been guided/biased by PSA level. However, he notes that PSA testing has significant variability and inherent bias. It is by no means a perfect test.
This study, which is currently in the process of publication, was a phase 3 randomized study directly comparing prostate MRI to PSA testing in a population of screening naïve man. The primary outcome was the diagnosis of prostate cancer and specifically clinically significant prostate cancer. Men were randomized in a 1:1 fashion to either prostate MRI or PSA testing.
Eligible subjects include:
- Men 50 years or older
- No prior PSA in 3 years (verified by a province wide database)
- Normal DRE
- No prior biopsy
- No family history of prostate cancer
- Asymptomatic
The strength of the Ontario provincial registry is that study authors could easily look at any patient’s prior history to ensure no prior screening or testing. They advertised for the study using newspaper and radio advertisements.
In men randomized to PSA testing,
- If PSA between 2.6-4.0, they were offered TRUS-guided prostate biopsy
- If PSA > 4.0, mandatory TRUS-guided prostate biopsy was performed
In men randomized to MRI,
- Biparametric MRI (no contrast) was completed to expedite evaluate
- PIRADS 4-5 lesions underwent mandatory US-MRI fusion biopsy
- End of study PSA was performed
He then spent some time on enrollment:
Interestingly, 1188 men responded – but 663 were excluded, mostly because men with prior PSA testing really wanted an MRI, indicating the interest amongst the public for MRI evaluation.
Ultimately, 525 men randomized.
- Some men randomized to PSA testing withdrew because they were adamant about getting MRI and avoiding PSA testing
He, unfortunately, did not get into the details of the results, as the study is under review and pending publication. However, he did hint that MRI as a screening tool resulted in ~50% less prostate biopsies – but significantly higher prostate cancer (and clinically significant prostate cancer) diagnoses.
More importantly, the study demonstrates the public’s knowledge of prostate MRI value and their interest to avoid PSA testing and prostate biopsy.
Presented by: Robert Nam, MD, Sunnybrook Research Institute, Toronto, Canada
Written by: Thenappan (Thenu) Chandrasekar, MD – Urologic Oncologist, Assistant Professor of Urology, Sidney Kimmel Cancer Center, Thomas Jefferson University, @tchandra_uromd on Twitter during the 2021 European Association of Urology, EAU 2021- Virtual Meeting, July 8-12, 2021.