Few prospective studies have focused on the performance of the Prostate Health Index (PHI) in Asian populations. Therefore, we aimed to evaluate the performance of the PHI in predicting prostate cancer compared to standard prostate-specific antigen (PSA) tests.
We prospectively enrolled patients with suspected prostate cancer with a total PSA (tPSA) level 4-10 ng/ml or tPSA < 4 ng/ml and a suspicious digital rectal examination between February 2017 and September 2018. All of the patients underwent a 12-core transrectal ultrasound-guided prostate biopsy. Pre-biopsy blood samples were analyzed for tPSA, free PSA (fPSA), percentage of fPSA (%fPSA), [-2]proPSA (p2PSA) and percentage of p2PSA (%p2PSA). The PHI was calculated as (p2PSA/fPSA) x √tPSA. The areas under the receiver operating characteristic curve (AUCs) were estimated for the PSA derivatives in addition to their specificities at a prespecified sensitivity of 90%.
Of the 307 enrolled patients, 95 (30.9%) had prostate cancer on biopsy. Excluding fPSA, all of the PSA derivatives were significantly different between the positive and negative biopsy groups. Of the various derivatives, the PHI (AUC: 0.783) showed the best performance in predicting the results of the initial biopsy compared to tPSA (AUC: 0.611). At a sensitivity of 90%, the PHI had the best specificity of 46.7% compared to 23.2% for tPSA. Using a PHI cutoff value of 35.15 for biopsy, 108 (35.2%) patients could have avoided undergoing a biopsy. To detect Gleason score ≥ 7 disease at 90% sensitivity, the threshold for PHI was 36.96 with a specificity of 52.1%.
PHI was the best biomarker among the PSA derivatives in predicting prostate cancer at biopsy in men with tPSA < 10 ng/ml. The risk of a Gleason score ≥ 7 increased with increasing PHI.
Journal of the Chinese Medical Association : JCMA. 2019 Jul 22 [Epub ahead of print]
Yu-Hua Fan, Po-Hsun Pan, Tzu-Ping Lin, Tzu-Hao Huang, Tzu-Chun Wei, I-Shen Huang, Chih-Chieh Lin, Eric Y H Huang, Hsiao-Jen Chung, William J S Huang
Department of Urology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.