Efficacy and Safety Differences Between Abiraterone and Enzalutamide in Patients with Metastatic Castration-Resistant Prostate Cancer: A Systematic Review and Meta-analysis of Real-World Studies

Abiraterone (ABI) and enzalutamide (ENZA) are standard treatments for metastatic castration-resistant prostate cancer (mCRPC). However, their safety and efficacy have not been directly compared in prospective clinical trials. To directly compare their safety and efficacy in prospective clinical trials. A systematic search was performed in PubMed, Embase, and Cochrane Library databases (CRD42024608496) on 24 June 2025. Eligibility criteria included studies on patients with mCRPC treated with ABI or ENZA reporting outcomes such as overall survival (OS), prostate-specific antigen (PSA) response (PSA50/90), progression-free survival (rPFS/bPFS), and rates of grade ≥ 3 adverse events, dose reduction, treatment discontinuation, and major cardiovascular events (MACE). Both first- and second-line mCRPC treatment settings were considered. The inverse variance method was used to calculate pooled hazard ratios (HRs), using the natural logarithm of the HR and its standard error (SE) from the available data. A total of 47 real-world observation studies and data from 71,984 patients were included, with no randomized controlled trials available for direct comparison. ENZA proved more effective in terms of PSA50 (odds ratio (OR): 1.82; 95