Multicenter randomized phase 2 trial of metastases-directed therapy to standard systemic therapy for oligometastatic castration-resistant prostate cancer

The randomized phase 2 GROUQ-PCS 9 trial, at 13 centers in Canada, evaluated addition of SBRT (to all metastatic sites) to standard systemic androgen deprivation therapy (ADT) plus enzalutamide (ENZA) therapy for castration-resistant prostate cancer with 5 or less metastases after progression on ADT. The median radiographic progression-free survival was 4.6 years with SBRT-ADT-ENZA versus 2.3 years with ADT-ENZA. The toxicity profiles were similar between the groups. The authors conclude that these findings support integrating SBRT into the treatment paradigm for oligometastatic CPRC.