New research provides additional support for MRI’s role in making prostate screening more effective. In a new study in NEJM, researchers found that MRI can help reduce unnecessary biopsies more than 50%, with a very low chance of missing high-risk disease.
As we’ve discussed in previous newsletters, prostate cancer screening based on PSA levels is an imprecise test.
- Many men with suspiciously high PSA (typically 3-4 ng/mL or higher) undergo biopsies that detect clinically insignificant disease that would never present a health risk during their lifetimes – the classic definition of overdiagnosis.
Adding MRI can help make prostate screening more precise by directing biopsy-based workup to only those men with clinically significant cancer – but questions still abound about exactly when it should be used.
In new results from the GÖTEBORG-2 trial in Sweden, researchers compared prostate screening protocols in men with PSA levels 3 ng/mL and higher who got MRI scans:
- One group automatically got systemic biopsy and then MRI-targeted biopsy based on MRI results.
- The other group only got MRI-targeted biopsy if they had a suspicious MRI scan.
In 13.2k men who were followed up for a median of four years, researchers found that those in whom systemic biopsy was omitted …
- Had 57% lower risk of clinically insignificant cancers.
- Had lower relative risk of clinically insignificant cancers in subsequent screening rounds (RR=0.25 vs. 0.49).
- Had 16% lower risk of detecting clinically significant cancers.
- Had 35% lower risk of advanced or high-risk cancers.
On the down side, the protocol eliminating systemic biopsy could lead to later diagnoses for higher-risk disease for 3 in 1k men – but given the slow-growing nature of prostate cancer it’s not clear how significant this is.
- Also, the data indicate that “most prostate cancers become visible on MRI” before they are incurable, which increases the likelihood that they would at least be detected on subsequent screening rounds and could be treated effectively.
The Takeaway
The new findings should help clinicians hone in on the best prostate screening protocols for maximizing detection of clinically significant cancer while minimizing unnecessary workup. Hopefully, the addition of new technologies like AI can move this process along.
