Schiff JP, et al. - In this single-center retrospective study, researchers assessed early prostate-specific antigen decline and link to overall survival in patients who received abiraterone (without prior enzalutamide) for metastatic castrate-resistant prostate cancer. This study included overall 110 patients. At 4, 8, or 12 weeks, they found that prostate-specific antigen decline was either > 30% or > 50%, which was related to improved overall survival at all time points except > 50% decline at 8 weeks. To inform both patients and physicians regarding metastatic castrate-resistant prostate cancer outcomes post-abiraterone initiation, it is valid to use prostate-specific antigen responses as early as 4 weeks post-abiraterone initiation.