Multicenter phase 2 study of abiraterone acetate with or without stereotactic body radiotherapy for oligometastatic castration-resistant prostate cancer

The value of addition of stereotactic body radiotherapy (SBRT) to standard systemic treatment in men with oligometastatic (3 or less nonvisceral metastases) castration-resistant prostate cancer (CRPC) is not clear. The multicenter randomized phase 2 ARTO trial in Italy evaluated first-line abiraterone acetate plus prednisone (AAP) with or without SBRT to all metastases in oligometastatic CRPC. The SBRT group had better biochemical response (OR 5,34; p=0,001), complete biochemical response (OR 4.22; p<0.001), and progression-free survival (HR 0,35; p<0.001). Addition of SBRT to AAP did not result in increased rate of adverse events. The authors conclude that addition of SBRT to first-line AAP benefits patients with oligometastatic CRPC.