Stockholm3 Detected More Significant Prostate Cancers Than PSA

In a Swedish population-based screening cohort, the blood-based risk model had higher short-term sensitivity for clinically significant prostate cancer than prostate-specific antigen testing, with similar specificity.

By
Andrea Surnit
June 25, 2026
5 min

Conexiant

Objective:

To evaluate the effectiveness of the Stockholm3 blood-based screening test compared to prostate-specific antigen (PSA) testing in detecting clinically significant prostate cancers.

Approach:

Study Design: Secondary analysis of the STHLM3-MRI trial involving 12,670 men aged 50 to 74 years who underwent both PSA testing and Stockholm3 screening.
Outcome Assessment: Clinically significant prostate cancer was defined as grade group 2 or higher diagnosed within 2 years, assessed through linkage to cancer registries.
Screening Methodology: Men with PSA levels of 3 ng/mL or greater or Stockholm3 scores of 11 or greater were referred for further workup, while negative results did not routinely lead to biopsy.

Key Findings:

Stockholm3 detected 400 clinically significant cancers with a sensitivity of 90%, compared to 327 cancers detected by PSA testing with a sensitivity of 74%.
Stockholm3 missed 43 clinically significant cancers, while PSA testing missed 116.
False-negative rates were 10% for Stockholm3 and 26% for PSA testing.
Specificity was similar for both tests, at 89% for Stockholm3 and 90% for PSA.
Per 1,000 men screened, Stockholm3 detected about 32 clinically significant cancers compared to 26 by PSA testing.

Interpretation:

Limitations:

Participation among invited men was approximately 25%, limiting generalizability.
Baseline MRI and biopsy were only performed among men with positive screening results, affecting diagnostic accuracy estimates.
Follow-up was limited to 2 years, restricting assessment of long-term outcomes.
The cohort was predominantly Swedish or European, which may affect applicability to other populations.