Date Published:

2015 Jul 24

Abstract:

OBJECTIVE: To determine whether patients with Gleason score 5+3=8 prostate cancer have outcomes more similar to other patients with Gleason 8 disease or to patients with Gleason 9 disease. PATIENTS AND METHODS: The SEER database was used to study 40,533 men diagnosed with N0M0 Gleason 8 or 9 prostate cancer from 2004 - 2011. Using Gleason 4+4=8 as the referent, Fine and Gray competing risks regression analyses modeled the association between Gleason score and prostate cancer-specific mortality (PCSM). RESULTS: Five-year PCSM rates for patients with Gleason 4+4=8, Gleason 3+5=8, Gleason 5+3=8, and Gleason 9 disease were 6.3%, 6.6%, 13.5%, and 13.9%, respectively (P<0.001). Patients with Gleason 5+3=8 or Gleason 9 disease had up to a two-fold increased risk for PCSM ([Adjusted Hazard Ratio (AHR) 1.89; 95% CI 1.50 - 2.38; P<0.001] and [AHR 2.17; 95% CI 1.99 - 2.36; P<0.001], respectively) compared to the referent group of patients (Gleason 4+4=8). There was no difference in PCSM between patients with Gleason 5+3=8 versus 9 disease (P=0.25). CONCLUSIONS: Gleason 8 disease represents a heterogeneous entity with PCSM outcomes distinguishable by the primary Gleason pattern. The PCSM of Gleason 3+5=8 and Gleason 4+4=8 disease are similar, but patients with Gleason 5+3=8 have a risk of PCSM that is twice as high as other patients with Gleason 8 disease and should be considered to have similar poor prognosis as patients with Gleason 9 disease. Such patients should be allowed onto trials seeking the highest-risk patients in which to test novel aggressive treatment strategies. This article is protected by copyright. All rights reserved.