Prostate health index density improves detection of clinically-significant prostate cancer

To explore the utility of prostate health index (PHI) density for detection of clinically-significant prostate cancer (PCa) in a contemporary cohort of men presenting for diagnostic workup of PCa.

The study cohort included patients with elevated PSA (>2 ng/ml) and negative digital rectal examination who underwent PHI testing and prostate biopsy at our institution in 2015. Serum markers were prospectively measured per standard clinical pathway. PHI was calculated as [([-2]proPSA/free PSA) x (PSA)(½) ], and density calculations were performed using prostate volume as determined on transrectal ultrasound. Logistic regression was used to assess the ability of serum markers to predict clinically-significant PCa, defined as any Gleason score ≥7 cancer or Gleason score 6 cancer in >2 cores or >50% of any positive core.

Of 118 men with PHI testing who underwent biopsy, 47 (39.8%) were found to have clinically-significant PCa on biopsy. The median PHI density was 0.70 (IQR 0.43-1.21); it was 0.53 (IQR 0.36-0.75) in men with negative biopsy or clinically-insignificant PCa and 1.21 (IQR 0.74-1.88) in men with clinically-significant PCa (p<0.001). Clinically-significant PCa was detected in 3.6% of men in the first quartile of PHI density (<0.43), 36.7% of men in the interquartile range (0.43-1.21) of PHI density, and 80.0% of men with PHI density >1.21 (p<0.001). Using a threshold of 0.43, PHI density was 97.9% sensitive and 38.0% specific for clinically-significant PCa, and 100% sensitive for Gleason score ≥7 disease. Compared to PSA (AUC 0.52), PSAD (AUC 0.70), %free PSA (AUC 0.75), the product of %free PSA and prostate volume (AUC 0.79), and PHI (AUC 0.76), PHI density demonstrated the highest discriminative ability for clinically-significant PCa (AUC 0.84).

Based on this prospective single-center experience, PHI density could be used to avoid 38% of unnecessary biopsies while failing to detect only 2% of clinically-significant cancers. This article is protected by copyright. All rights reserved.

BJU international. 2017 Jan 06 [Epub ahead of print]

Jeffrey J Tosoian, Sasha C Druskin, Darian Andreas, Patrick Mullane, Meera Chappidi, Sarah Joo, Kamyar Ghabili, Mufaddal Mamawala, Joseph Agostino, Ballentine H Carter, Alan W Partin, Lori J Sokoll, Ashley E Ross

The James Buchanan Brady Urological Institute and Department of Urology, the Johns Hopkins University School of Medicine.