We assessed whether Prostate Health Index (phi) results improve prediction of grade reclassification for men on active surveillance.
We identified men in Canary Prostate Active Surveillance Study with Grade Group (GG) 1 cancer. Outcome was grade reclassification to GG2+ cancer. We considered decision rules to maximize specificity with sensitivity set at 95%. We derived rules based on clinical data (R1) vs clinical data+phi (R3). We considered an "or"-logic rule combining clinical score and phi (R4), and a "two-step" rule using clinical data followed by risk stratification based on phi (R2). Rules were applied to a validation set, where values of R2 - R4 vs R1 for specificity and sensitivity were evaluated.
We included 1532 biopsies (n=610 discovery; n=922 validation) among 1142 men. Grade reclassification was seen in 27% of biopsies (23% discovery, 29% validation). Among discovery set, at 95% sensitivity, R2 yielded highest specificity at 27% vs 17% for R1. In validation set, R3 had best performance vs R1 with Δsensitivity = -4% and Δspecificity = +6%. There was slight improvement for R3 vs R1 for confirmatory biopsy (AUC 0.745 vs R1 0.724, ΔAUC=0.021, 95%CI 0.002-0.041) but not for subsequent biopsies (ΔAUC=-0.012, 95%CI -0.031-0.006). R3 did not have better discrimination vs R1 among the biopsy cohort overall (ΔAUC=0.007, 95%CI -0.007-0.020).
Among active surveillance patients, using phi with clinical data modestly improved prediction of grade reclassification on confirmatory biopsy and did not improve prediction on subsequent biopsies.
The Journal of urology. 2022 Jul 05 [Epub ahead of print]
Christopher P Filson, Kehao Zhu, Yijian Huang, Yingye Zheng, Lisa F Newcomb, Sierra Williams, James D Brooks, Peter R Carroll, Atreya Dash, William J Ellis, Martin E Gleave, Michael Liss, Frances Martin, Jesse K McKenney, Todd M Morgan, Andrew A Wagner, Lori J Sokoll, Martin G Sanda, Daniel W Chan, Daniel W Lin
Department of Urology, Emory University School of Medicine, Atlanta, Georgia., Biostatistics Program, Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington., Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia., Department of Urology, University of Washington, Seattle, Washington., Department of Urology, Stanford University, Stanford, California., Department of Urology, University of California, San Francisco, California., VA Puget Sound Health Care Systems, Seattle, Washington., Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia., Department of Urology, University of Texas Health Sciences Center, San Antonio, Texas., Department of Urology, Eastern Virginia Medical School, Virginia Beach, Virginia., Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio., Department of Urology, University of Michigan, Ann Arbor, Michigan., Division of Urology, Beth Israel Deaconess Medical Center, Boston, Massachusetts., Department of Pathology, Urology, and Oncology, Johns Hopkins University School of Medicine, Baltimore, Marylan.