The Value of Prostate-Specific Antigen-Related Indexes and Imaging Screening in the Diagnosis of Prostate Cancer.

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.