Sequential ADT and abiraterone acetate plus prednisone versus combined ADT with abiraterone acetate plus prednisone for metastatic castration-sensitive prostate cancer: A propensity score-matched study.

e17075 Background: Previous studies showed that combination of androgen deprivation therapy (ADT) with abiraterone acetate plus prednisone was associated with longer survival than ADT alone in patients with metastatic castration-sensitive prostate cancer (mCSPC). The aim of this retrospective propensity score-matched study was to compare the effects of sequential treatment of ADT and abiraterone acetate plus prednisone (sequential treatment cohort), and combination treatment of ADT with abiraterone acetate plus prednisone (combination treatment cohort), in men with newly diagnosed mCSPC. Methods: The sequential treatment cohort received ADT or ADT plus first-generation nonsteroidal antiandrogen (NSAA) as first-line therapy, then ADT and abiraterone acetate plus prednisone after progression. The combination treatment cohort received ADT and abiraterone acetate plus prednisone as first-line therapy. Patients with newly diagnosed mCSPC treated with ADT, ADT plus first-generation NSAA, or ADT plus abiraterone acetate in our center between June 2014 and July 2022, were respectively identified. Patients treated with sequential treatment or combination treatment were evaluated through propensity score matching (PSM) based on baseline clinical characteristics. The primary outcome was abiraterone failure-free survival (aFFS). Secondary outcomes including overall survival (OS), PSA response. Results: Clinical characteristics were balanced after PSM and 117 patients were included in each cohort. The aFFS was 30.7 and 30.6 months in sequential and combination treatment cohort, respectively, no statistically significant difference was observed (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.64 -1.27; p = 0.526). Similarly, there was no statistically significant difference in overall survival (OS, HR 0.92, 95% CI 0.57 -1.49; p = 0.388) between sequential and combination treatment. Conclusions: Patientswith newly diagnosed mCSPC treated with sequential ADT and abiraterone acetate plus prednisone, had similar aFFS and OS, compared to men treated with combined ADT and abiraterone acetate plus prednisone, according to our preliminary results. Our data indicate that sequential treatment of ADT and abiraterone acetate might be considered as an alternative to newly diagnosed mCSPC.