The performance of [-2]proPSA and prostate health index tumor markers in prostate cancer diagnosis

Background: Prostate-specific antigen (PSA) is an established tumor marker for the diagnosis of patients with prostate cancer. The aim of the study was to evaluate the performance of [-2]proenzyme PSA ([-2]proPSA) and prostate health index (PHI) tumor markers in the differential diagnosis between benign prostatic diseases and prostate cancer. Methods: Total PSA (tPSA), free PSA (fPSA) and [-2]proPSA were measured using antibody-based sandwich enzyme-linked immunosorbent assay with a chemiluminescent detection system in 110 patients, with a tPSA of 1.6–8.0 µg/L. The PHI and %[-2]proPSA were calculated from the PSA values mentioned above. The results were compared with histopathological examination results following a transrectal ultrasound-guided biopsy of the prostate. Results: For the prediction of a malignant histopathological result, the specificity at the 90% sensitivity level was 24.3% for [-2]proPSA, 32.4% for %[-2]proPSA, 28.4% for PHI, 18.9% for tPSA and 28.4% for the free-to-total PSA ratio. The area under the curve for [-2]proPSA, %[-2]proPSA, PHI, tPSA and the free-to-total PSA ratio was 0.663, 0.749, 0.742, 0.616 and 0.625, respectively. Conclusions: Our study found a moderate improvement over tPSA and %fPSA in detecting prostate cancer using the [-2]proPSA assay in patients with a tPSA range of 1.6–8.0 µg/L.