The Effects of the Blood-Based S2,3PSA% Test on Prostate Cancer Screening: A Novel Approach to Reduce the Need for MRI and Unnecessary Biopsies.

OBJECTIVE

Prostate-specific antigen (PSA)-based screening has reduced prostate cancer (PCa) mortality but is associated with overdiagnosis/overtreatment. We developed and evaluated a blood-based S2,3PSA% test to address the limitations of PSA-based screening for PCa.

METHODS

This retrospective study included men aged ≤ 75 years who underwent opportunistic PSA and S2,3PSA% screening between April 2022 and March 2023. Secondary screening was recommended for participants with PSA ≥ 2.0 ng/mL and S2,3PSA% ≥ 38.0%, or PSA ≥ 4.0 ng/mL. The primary outcome was the reduction in MRI utilization based on an S2,3PSA% cutoff of ≥ 38.0%. Secondary outcomes included the PCa detection rate, as well as reductions in prostate biopsies and medical costs.

RESULTS

Among 808 participants who underwent PSA and S2,3PSA% screening, 190 met the criteria for secondary screening. Of these, 72 underwent further evaluation, including MRI in 65 participants. MRI findings excluded 22 (33.8%) participants from requiring prostate biopsy. Ultimately, 25 participants underwent prostate biopsy, and PCa was diagnosed in 17 (68.0%), including 12 with clinically significant PCa. The combined use of PSA, S2,3PSA%, and MRI resulted in a 44% reduction in MRI use, a 63% reduction in unnecessary biopsies, and a 72% reduction in medical costs. Study limitations include the small sample size and lack of evaluation of participants with negative S2,3PSA% or MRI findings.

CONCLUSIONS

S2,3PSA% screening may have potential as a tool to reduce the need for MRI, unnecessary biopsies, and medical costs.