Impact of Percent Positive Biopsy Cores on Cancer-Specific Mortality for Patients with High-Risk Prostate Cancer

ABSTRACT Objective A high percent positive biopsy cores (PBC), typically dichotomized at ≥50% is prognostic of worse cancer-specific outcomes for patients with low- and intermediate-risk prostate cancer (CaP). The clinical significance of ≥50% PBC for patients with high-risk disease is poorly understood. We examined the association between ≥50% PBC, compared to Materials and methods We identified 7,569 men from the Surveillance, Epidemiology, and End Results program who were diagnosed with high-risk CaP (Gleason score of 8–10, prostate-specific antigen >20 ng/mL, or cT3-T4 stage) in 2010–2011 and had 6 to 24 cores sampled at biopsy. Multivariable Fine and Gray competing risks regression was utilized to examine the association between ≥50% PBC and PCSM. Results Median follow-up was 3.8 years. 56.2% of patients (4,253) had ≥50% PBC. On competing risks regression, ≥50% PBC was associated with a significantly higher risk of PCSM compared to Conclusion In this large cohort of patients with high-risk CaP, ≥50% PBC was independently associated with an approximately 2-fold increased risk of PCSM for patients with cT1–T2, but not cT3–T4, tumors. Percent PBC, which is a widely available clinical value, should be routinely used to risk stratify men with high-risk disease and identify patients whom may benefit from treatment intensification.