Objective: The aim of this study was to explore the value of the prostate-specific antigen (PSA) levels, the ratio of free PSA to total PSA (fPSA/TPSA), the PSA density (PSAD), digital rectal examination (DRE), transrectal prostate ultrasound (TRUS), and multiparameter MRI (MP-MRI) in the differential diagnosis of benign prostatic hyperplasia (BPH) and prostate cancer (PCa).
Methods: From February 2016 to September 2019, data from 620 patients who underwent systematic transrectal ultrasound-guided prostate biopsy (STURS-PB) in our hospital were retrospectively collected, including the PSA levels, the fPSA/TPSA ratio, the PSAD, DRE, TRUS, MP-MRI, prostate volume, and other clinical data.
Results: Among the 620 patients, 249 patients were in the PCa group, and 371 patients in the BPH group. The positive puncture rate was 40.16%. The positive predictive values of DRE, TRUS, mpMRI, and TPSA levels for PCa were 39.91%, 39.38%, 64.14%, and 41.57%, respectively; the sensitivity of these parameters was 37.35%, 51.41%, 74.69%, and 57.43%, respectively; and the specificity of these parameters was 62.26%, 46.90%, 71.97%, and 45.82%, respectively. When the TPSA concentration was in the range of 4– 20 ng/mL, the positive puncture rate of STURS-PB was 23.18%, with a high rate of misdiagnosis. When the TPSA concentration was in the range of 4– 20 ng/mL, the fPSA/TPSA ratio was 0.15, the PSAD was 0.16, the comprehensive evaluation of PCa was optimal (the sensitivity of these parameters was 88.85% and 84.09%, respectively; the specificity was 80.17% and 67.29%, respectively; the positive predictive value was 57.41% and 51.39%, respectively). When the TPSA concentration > 4 ng/mL, the fPSA/TPSA ratio ≤ 0.15 and the PSAD ≥ 0.16, the sensitivity, specificity, and correctness index of the PCa and BPH diagnosis were 80.54%, 82.75%, and 67.07%, respectively.
Conclusion: When using DRE, TRUS, and MP-MRI to screen for PCa, MP-MRI has a relatively high sensitivity and specificity. Using these three thresholds (TPSA > 4 ng/mL combined with an fPSA/TPSA ratio ≤ 0.15 and a PSAD ≥ 0.16) is significantly better than using TPSA levels alone for the differential diagnosis of PCa and BPH.
Keywords: total prostate-specific antigen, free prostate-specific antigen, prostate-specific antigen density, prostate cancer, benign prostatic hyperplasia