Extended use of Prostate Health Index and percentage of [-2]pro-prostate-specific antigen in Chinese men with prostate specific antigen 10–20 ng/mL and normal digital rectal examination

PURPOSE We investigated the extended use of Prostate Health Index (PHI) and percentage of [-2]pro-prostate-specific antigen (%p2PSA) in Chinese men with prostate-specific antigen (PSA) 10-20 ng/mL and normal digital rectal examination (DRE). MATERIALS AND METHODS All consecutive Chinese men with PSA 10-20 ng/mL and normal DRE who agreed for transrectal ultrasound (TRUS)-guided 10-core prostate biopsy were recruited. Blood samples were taken immediately before TRUS-guided prostate biopsy. The performances of total PSA (tPSA), %free-to-total PSA (%fPSA), %p2PSA, and PHI were compared using logistic regression, receiver operating characteristic, and decision curve analyses (DCA). RESULTS From 2008 to 2015, 312 consecutive Chinese men were included. Among them, 53 out of 312 (17.0%) men were diagnosed to have prostate cancer on biopsy. The proportions of men with positive biopsies were 6.7% in PHI<35, 22.8% in PHI 35-55, and 54.5% in PHI>55 (chi-square test, p<0.001). The area under curves (AUC) of the base model including age, tPSA and status of initial/repeated biopsy was 0.64. Adding %p2PSA and PHI to the base model improved the AUC to 0.79 (p<0.001) and 0.78 (p<0.001), respectively, and provided net clinical benefit in DCA. The positive biopsy rates of Gleason 7 or above prostate cancers were 2.2% for PHI<35, 7.9% for PHI 35-55, and 36.4% for PHI>55 (chi-square test, p<0.001). By utilizing the PHI cutoff of 35 to men with PSA 10-20 ng/mL and normal DRE, 57.1% (178 of 312) biopsies could be avoided. CONCLUSIONS Both PHI and %p2PSA performed well in predicting prostate cancer and high grade prostate cancer. The use of PHI and %p2PSA should be extended to Chinese men with PSA 10-20 ng/mL and normal DRE.