Primary MRI versus PSA-gated scans in Prostate Cancer Screening - how ready is it for mainstream implementation?

Abnormal PSA test results leading to MRI scans is mainstream practice in prostate cancer diagnosis. However, a similar algorithm may lead to under-detection of clinically significant prostate cancer (csPCa) in disease screening. We compare cancer detection rates (CDR) in screening with MRI prostate only ('primary' MRI) compared to MRI scans triggered by abnormal serum PSA levels ('PSA-gated' MRI).

Pubmed, Embase, Web of Science, CENTRAL, Scopus and Google Scholar were searched using key terms of "MRI", "prostate cancer", and "screening" from 01/1/2000-20/4/2024. We included studies investigating the general adult male population not otherwise risk stratified, and extracted outcomes of CDR for csPCa (ISUP Grade Group ≥ 2) and clinically insignificant prostate cancer (ciPCa) (ISUP Grade Group 1), and biopsy rate.

17 studies were included for final analysis. When including all studies, primary MRI had a higher CDR compared to PSA-gated MRI for all prostate cancer (8.49% vs. 1.88%, p = 0.0223) and csPCa (5.93% vs. 1.15%, p = 0.0180) detection respectively. There was no statistically significant difference in CDR for ciPCa between both groups. In studies directly comparing primary and PSA-gated MRI, primary MRI demonstrated higher odds of detection for all prostate cancer (OR 2.77, 95%CI: 1.71-4.49), csPCa (OR 2.32, 95%CI: 1.37-3.96) and ciPCa (OR 3.11, 95%CI: 1.08-8.97). Limitations include verification bias and heterogeneity between studies.

Primary MRI screening demonstrated higher CDR for csPCa than PSA-gated MRI screening triggered at PSA thresholds of 3-4 ng/ml. There is also higher CDR of ciPCa and adoption of needle biopsies. More granular cost-effectiveness outcomes are required before mainstream implementation is possible.