Survival Outcomes with Abiraterone versus Enzalutamide in Metastatic Prostate Cancer: A Real-World Single-Center Study

INTRODUCTION: Abiraterone acetate and enzalutamide are widely used androgen receptor-targeted therapies for metastatic prostate cancer (mPCa). Although both agents have demonstrated survival benefits in randomized trials, comparative real-world evidence remains limited. This study aimed to compare survival outcomes associated with abiraterone and enzalutamide and to evaluate the prognostic impact in patients with mPCa.
METHODS: This retrospective single-center study included 230 patients with mPCa treated with abiraterone (n=109) or enzalutamide (n=121). Overall survival (OS) and progression-free survival (PFS) were calculated from treatment initiation using the Kaplan–Meier method and compared with log-rank tests. Multivariable Cox proportional hazards regression analyses were performed adjusting for age, ECOG performance status, PSA level at treatment initiation, metastatic burden, treatment line, and hormone sensitivity status
RESULTS: The median follow-up duration was 21.1 months (IQR, 12.9–31.1 months). Patients receiving abiraterone were older and had higher PSA levels, poorer ECOG performance status, and greater metastatic burden than those receiving enzalutamide. In unadjusted analyses, enzalutamide was associated with longer OS (33.4 vs. 26.7 months, p=0.019) and PFS (53.6 vs. 17.5 months, p=0.006). Hormone-sensitive patients demonstrated superior OS (36.6 vs. 26.8 months, p=0.013) and PFS (36.6 vs. 14.4 months, p=0.001) compared with hormone-resistant patients. In multivariable Cox regression analysis, enzalutamide was not independently associated with improved OS (HR 0.85, 95% CI 0.54–1.33, p=0.468), but remained independently associated with improved PFS (HR 0.62, 95% CI 0.39–0.98, p=0.042).
DISCUSSION AND CONCLUSION: In this real-world cohort, enzalutamide remained independently associated with improved PFS after adjustment for baseline prognostic factors, whereas the difference in overall survival was no longer statistically significant.

Keywords: metastatic prostate cancer, abiraterone, enzalutamide, overall survival, progression-free survival.