Key clinical point: Stereotactic ablative radiotherapy (SABR) improves oncological outcomes and delays progression in patients with oligometastatic prostate cancer vs. observation.

Major finding: At 6 months, disease progression was reported in 19% of patients receiving SABR and 61% of those undergoing observation (P = .005). SABR vs. observation improved median progression-free survival (not reached vs. 5.8 months; hazard ratio, 0.30; P = .002).

Study details: In this ORIOLE phase 2 trial, 54 patients with recurrent hormone-sensitive oligometastatic prostate cancer were randomly assigned 2:1 to receive SABR or observation.

Disclosures: This study was supported by the Nesbitt-McMaster Foundation, Ronald Rose and Joan Lazar, the Movember Foundation and Prostate Cancer Foundation, and the National Cancer Institute; SDW/DT and Shanahan Cancer Research Funds; the U.S. National Institutes of Health Director’s New Innovator Award; the Virginia and D.K. Ludwig Fund for Cancer Research; the CRK Faculty Scholar Fund; and the Transdisciplinary Integration of Population Science Program of Sidney Kimmel Cancer Center–Jefferson Health and a Challenge Grant from the Prostate Cancer Foundation. The authors reported receiving grants and personal fees from multiple pharmaceutical companies.

Citation: Phillips R et al. JAMA Oncol. 2020 Mar 26. doi: 10.1001/jamaoncol.2020.0147.

Commentary

“Traditionally, systemic treatment for metastatic cancers of all types, not just prostate cancer, has been considered the standard of care. However, emerging data in oligometastatic disease in prostate and other cancers supports the hypothesis that oligometastatic disease may be distinct from more widespread metastatic cancer and that localized treatments may be beneficial. Stereotactic ablative radiotherapy (SABR) is a well-tolerated approach currently under investigation. In the ORIOLE phase 2 trial, men with recurrent hormone-sensitive prostate cancer and 1-3 metastases were randomized to SABR or observation. Progression of disease was significantly lower in the group receiving SABR. Thus, larger randomized trials are certainly warranted to continue to determine the optimal role for SABR in patients with oligometastatic prostate cancer.”

Mark Klein, MD