This is a Phase III non-blinded randomized study evaluating patients with oligometastatic cancers (up to 10 metastases). Subjects are randomized 1:1 to stereotactic ablative radiotherapy (SABR) plus standard of care therapies versus SABR alone. The investigators will measure progression-free survival at 2 years based on the hypothesis that subjects treated with SABR plus standard of care will not experience disease progression for a longer period of time than subjects treated with standard of care alone. The investigators will also measure overall survival and safety of SABR, as well as biomarkers that may help predict, in the future, who will benefit from the SABR treatment.
Patients with metastatic solid malignancies are generally deemed incurable. Systemic therapies (cytotoxic chemotherapy, immunotherapy, hormonal therapy, etc.) can be effective for prolonging life, but cancers will eventually become resistant, prompting transition to second-line therapies that are often more toxic and/or more expensive with diminishing oncologic benefit. In patients with relatively few detectable metastases, SABR to visible tumors may substantially delay progression and thus improve quality of life. Unfortunately, most patients with metastatic disease will eventually die from their cancer. Stereotactic ablative radiotherapy (SABR) is highly effective, often achieving long-term local control. Previous studies demonstrated that SABR improves survival and quality of life in patients with oligometastatic cancer. However, these studies were small and not randomized. Thus, this randomized study will better evaluate the efficacy and safety of SABR in oligometastatic cancer.
