Real-World Clinical Evaluation of S2,3PSA Test in a Prostate Biopsy Cohort With PSA Level of 4-10 ng/mL

Prostate-specific antigen (PSA) is a widely used prostate cancer marker; however, its use is limited by its low specificity. Novel biomarkers are being explored to avoid unnecessary biopsies. A new prostate cancer marker, S2,3PSA, became eligible for insurance coverage in February 2024.

A total of 144 patients underwent S2,3PSA measurement prior to prostate biopsy at Asahikawa Kosei Hospital and Teine Keijinkai Hospital. PI-RADS score on MRI, PSA level, prostate volume (PV), and Gleason score were retrieved from medical records.

The median age of the patients was 69 years, the median PSA level was 5.79 ng/mL, and prebiopsy MRI PI-RADS scores were 2 or less (43 patients), 3 (31 patients), 4 or greater (64 patients), and without MRI (6 patients). The median PV was 43 cm³. The median S2,3PSA was 41.85%. Of the cases examined, 55 (38%) exhibited prostate cancer and 36 (25%) were classified as significant cancer (SC, defined as Gleason Group 2 or higher). S2,3PSA and S2,3PSAD levels were significantly higher in the cancer group than the non-cancer group, and in the SC group than in the no-SC group. The AUC was 0.609 and 0.688 in the cancer group, and 0.646 and 0.703 in the SC group. Of the cases with MRI PI-RADS 2 or lower, two cases (4.6%) were identified as SC, and these cases exhibited elevated S2,3PSA and S2,3PSAD.

The AUC observed in this study was lower than that reported in previous studies. The efficacy of S2,3PSA may be enhanced when used in combination with MRI. Prostate biopsy may be unnecessary in cases where an MRI scan is negative and the S2,3PSA or S2,3PSAD levels are low.