Assessment of two prognostic risk group methods to predict outcomes with docetaxel-based therapy in men with metastatic castration-resistant prostate cancer (mCRPC).

185 Background: Threeprognosticrisk groups have been identified in men with mCRPC (good [GR]/intermediate [IR]/poor [PR]) based on 0-1, 2 or 3-4 factors (visceral disease, pain, anemia, bone scan progression). Prostate Cancer Working Group (PCWG)-2 defines clinical subtypes with visceral disease, bone metastases ± nodal metastases and nodal disease only. The prognostic ability of risk grouping or PCWG2 subtypes was evaluated in a large, independent phase II trial. Methods: A randomized phase IItrial of 221 men with mCRPC that received docetaxel-prednisone (DP) + AT-101 (Bcl-2 inhibitor) or DP + placebo was retrospectively analyzed using Cox regression and χ tests. Additional outcomes, tests and measures of discriminatory ability were assessed and will be presented. Patients from both groups were combined for analysis, as no significant differences in outcomes were observed. Results: 93, 81 and 38 men had GR, IR and PR disease. GR men were more likely than IR/PR men to be ECOG-PS 0 (48%, 27%, 21%) and had a lower median baseline PSA (63, 85, 193 ng/ml). Significant differences between risk groups were observed for progression-free survival (PFS, p=0.009) and overall survival (OS, p<0.001), while PCWG2 subtypes did not discriminate for these outcomes. Both risk groups and PCWG2 subtypes inconsistently predicted PSA declines (table). Conclusions: Prognostic risk groups significantly distinguished between outcomes in men with mCRPC receiving DP-based therapy, while PCWG2 subtypes did not. Risk groups may enhance stratification of patients in randomized trials and enable tailored drug development. Prognostic models that incorporate tumor molecular features may improve discriminatory ability. [Table: see text] [Table: see text]

Duke Scholars

Author Andrew John Armstrong Medicine, Medical Oncology