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The following is a summary of “Performance of 4Kscore as a Reflex Test to Prostate-Specific Antigen in the GÖTEBORG-2 Prostate Cancer Screening Trial,” published in the May 2024 issue of Urology by Josefsson et al.

This study aimed to evaluate the potential of integrating 4Kscore as a reflex test to Prostate-Specific Antigen (PSA) in improving prostate cancer (PC) screening protocols. Within the GÖTEBORG-2 PC screening trial, 38,000 men aged 50-60 underwent PSA testing, followed by magnetic resonance imaging (MRI) for those with elevated PSA levels. Among 571 men with PSA ≥3.0 ng/ml, 4Kscore was calculated to assess its performance in predicting PC risk using a predefined cutoff of 7.5%.

The area under the curve (AUC) for 4Kscore in identifying intermediate- and high-risk PC was 0.84 (95% CI 0.79-0.89). The positive predictive value was 15% (95% CI 12-20%), and the negative predictive value was 99% (95% CI 97-100%). Among the 54 men diagnosed with intermediate- or high-grade PC, two had a 4Kscore below 7.5%, both with organ-confined intermediate-risk PC. Incorporating the 4Kscore into the screening protocol would have reduced MRI referrals by 41%, biopsies by 28%, and overdiagnosis of low-grade cancers by 23% while delaying diagnosis of intermediate-grade cancers in four men per 1000.

The inclusion of 4Kscore as a reflex test for men with elevated PSA levels significantly reduces the need for resource-intensive MRI and biopsies. It effectively balances the reduction in overdiagnosis of low-grade PC with potential delays in diagnosing intermediate-grade PC. These findings support the integration of novel blood-based biomarkers alongside PSA to optimize the risk-benefit ratio of PC screening, offering a practical approach to enhance clinical decision-making and resource allocation in PC management.

Source: sciencedirect.com/science/article/pii/S0302283824023790