Balancing Overdiagnosis and Early Detection of Prostate Cancer using the Stockholm-3 Model

The S3M (Stockholm-3 Model) test improves discrimination for high-grade (Gleason score ≥ 7) prostate cancer compared with prostate-specific antigen (PSA) testing. Published results from the Stockholm-3 study represent a snapshot of possible outcomes for prostate cancer detection using the S3M test. In this brief report, we show how the full range of cancer detection rates and percent saved biopsies depend on the chosen S3M cut-off for recommending prostate biopsy. Using data from the Stockholm-3 validation cohort (n=47 688), we calculated the cancer detection rates and percent saved biopsies for various S3M test cut-offs in men with PSA ≥1ng/ml. Cancer detection rates decline and fewer prostate biopsies have to be performed with increasing test cut-offs. Primarily, S3M test values between 7% and 14% can be considered for biopsy decision cut-offs (10% risk of Gleason score ≥ 7 corresponds to PSA=3 ng/ml); the exact cutoff can be chosen to fit different healthcare systems and, indeed, individual men. PATIENT SUMMARY: The Stockholm-3 Model test improves the detection of high-grade prostate cancer compared with prostate-specific antigen. In this brief report, we show how the cut-off used for recommending prostate biopsies affects the number of detected cancers and performed biopsies. The exact cut-off used can be chosen to fit different individuals and healthcare systems.