Stockholm3-Magnetic Resonance Imaging Population-Based Prostate Cancer Screening Study: Two-Year Follow-up

Area of Science:

• Urology
• Oncology
• Medical Diagnostics

Background:

• Prostate-specific antigen (PSA) testing for prostate cancer screening is controversial due to its limitations.
• The Stockholm3 test offers an alternative approach, integrating PSA, plasma protein biomarkers, polygenic risk, and clinical factors into a multivariable risk score.

Purpose of the Study:

• To compare the detection rates of clinically significant prostate cancer (csPC) between the PSA test and the Stockholm3 test in a population-based screening setting.
• To evaluate the performance of both screening methods in terms of sensitivity, specificity, and false-negative/positive rates.

Main Methods:

• Secondary analysis of the STHLM3-MRI randomized screening trial involving men aged 50–74.
• Comparison of PSA (≥3 ng/mL) and Stockholm3 (≥11) screening results against biopsy-confirmed csPC (grade group ≥2) diagnosed within 2 years.
• Utilized decision curve analysis to assess the clinical net benefit of each screening strategy.

Main Results:

• Stockholm3 demonstrated a higher sensitivity (90%) for detecting csPC compared to PSA (74%), with similar specificity.
• Stockholm3 had a lower false-negative rate (10%) than PSA (26%), indicating fewer missed csPC cases.
• Decision curve analysis favored Stockholm3, suggesting a higher net benefit by reducing both unnecessary biopsies and missed csPC diagnoses.

Conclusions:

• The Stockholm3 test provides a greater clinical net benefit for detecting csPC in a screening cohort compared to the traditional PSA test.
• The improved performance of Stockholm3 is primarily attributed to its significantly lower false-negative rate.
• While promising, the study's findings are based on short-term follow-up and a predominantly European cohort, necessitating further research for broader generalizability.