Prognostic Value of Automated Bone Scan Index in Men With Metastatic Castration-resistant Prostate Cancer Treated With Enzalutamide or Abiraterone Acetate
Bone scan index (BSI) is an objective tool for quantifying bone metastasis load. We assessed its prognostic usefulness in patients with metastatic castration-resistant prostate cancer (CRPC) treated with enzalutamide (ENZ) or abiraterone acetate (AA).Materials and Methods
We analyzed 40 patients who received ENZ or AA treatment (ENZ/AA) for metastatic CRPC. The Cox proportional hazards model and a C-index were used to investigate associations between overall survival (OS) and BSI, and patient age, prostate-specific antigen, time to CRPC, previous docetaxel use, and pain.Results
Median OS after ENZ/AA was 17.8 months. All patient deaths (n = 19; 47.5%) were from prostate cancer. In multivariate analysis, decreased BSI was an independent predictor for longer OS (hazard ratio, 8.97; P = .011). Inclusion of BSI improved the C-index from 0.721 to 0.792 in predicting OS after ENZ/AA.Conclusions
Decreased BSI after ENZ/AA independently predicts longer OS.Micro-Abstract
We retrospectively assessed the bone scan index as a predictor of overall survival in patients with metastatic castration-resistant prostate cancer treated with enzalutamide or abiraterone acetate. Improved bone scan index after these treatments independently predicted longer overall survival.