The Prostate Health Index (PHI) can help predict high-stage prostate cancer (PCa) in African American men, according to a small study.
Previous research has demonstrated the promise of the index—a composite of total prostate-specific antigen (PSA), free PSA, and p2PSA—for screening and active surveillance in Caucasian and Asian patients, but data on African American patients have been limited. African American men tend to have more aggressive PCa, and better prognostic tools that predict adverse pathology are needed.
For the retrospective study, Zeyad R. Schwen, MD, Jeffrey J. Tosoian, MD, and colleagues of the Brady Urological Institute at Johns Hopkins Medical Institutions in Baltimore, assessed pre-operative PHI for 80 African American patients with PSA 2–10 ng/mL and compared it to pathology findings following radical prostatectomy.
One fifth of patients had pathological stage 3 (pT3) disease, according to results published in Urology online ahead of print. Although age, PSA, and percentage free PSA values were similar among patients, PHI was significantly greater in African American men with pT3.
Adding PHI to a model that included digital rectal exam findings (but not Gleason score or percentage of positive cores) improved its diagnostic accuracy by 12.9% compared with models using other biomarkers, such as PSA or percentage free PSA.
“Acknowledging the limited sample size explored in this study, our findings mirror previous findings in the overall population that suggest PHI may improve upon currently available methods for predicting high-stage PCa in the AA population,” the investigators stated.
A PHI value greater than 50 was associated with greater odds of non-organ-confined disease, but future studies in larger numbers of patients are still needed to determine the best thresholds for discriminating high-risk and lowest risk disease.