Real‑world survival outcome comparing abiraterone acetate plus prednisone and enzalutamide for nonmetastatic castration‐resistant prostate cancer

BACKGROUND: There is little evidence of abiraterone acetate (AA) plus prednisone for patients with non‐metastatic castration‐resistant prostate cancer (nmCRPC). In this study, we conducted a comparative analysis of real‐world survival outcomes between AA plus prednisone and enzalutamide (Enz) in patients with nmCRPC, utilizing our consortium dataset. MATERIALS AND METHODS: The clinical records of 133 nmCRPC patients treated with first‐line Enz or AA plus prednisone were analyzed. The primary endpoints of the study were overall survival (OS) and cancer‐specific survival (CSS). Cumulative incidence function (CIF) using Fine and Gray models was also utilized to assess non‐cancer‐caused death considering the competing risk of cancer‐caused death. RESULTS: During a median follow‐up of 36 months, 34 patients (25.6%) had deceased, with a median OS of 99 months in the entire cohort. There were no significant differences in comorbidities between the Enz and AA groups. Time to PSA progression (TTPP: HR 0.81, 95% CI 0.51–1.30, P = 0.375) and CSS (HR 1.32, 95% CI 0.55–3.44, P = 0.5141) were comparable between the two groups. However, intriguingly, there was a trend towards shorter OS in patients treated with AA plus prednisone compared to Enz (HR 0.57, 95% CI 0.29–1.12, P = 0.0978, median of 99 and 69 months in Enz and AA groups, respectively). CIF analysis revealed that nmCRPC patients treated with AA plus prednisone were more likely to result in non‐cancer‐caused death than those treated with Enz (HR 5.22, 95% CI 1.88–14.50, P = 0.0014). CONCLUSIONS: Our real‐world survival analysis suggests that while AA plus prednisone may demonstrate comparable treatment efficacy to Enz in the context of nmCRPC, there may be an increased risk of non‐cancer‐caused death. Physicians should take into consideration this information when making treatment decisions for patients with nmCRPC.