Multicenter randomized trial of metastases-directed treatment in patients with oligometastatic breast cancer

The OLIGOMA trial, at 31 centers in Germany and Austria, evaluated efficacy and tolerability of local radiation therapy to all metastases in patients with oligometastatic breast cancer (up to 5 metastases). A total of 87 patients with an indication for palliative systemic drug therapy were randomized 1:1 to the control group (drug therapy alone, palliative radiation permitted) or the experimental group (additional local therapy, preferably local radiotherapy). Co-primary endpoints were progression-free survival (PFS; superiority) and quality of life 12 weeks after randomization (noninferiority). The median PFS was 20.6 months (95% CI 12.5-28.6) in the control group and 36.2 months (24.3-ND) in the experimental group (HR 0.48; p=0.022). The quality-of-life analysis demonstrated non-inferiority for the experimental group compared to the control group. The authors conclude that addition of metastases-directed local therapy to systemic drug therapy was associated with improved PFS without impairment of quality of life in patients with oliometastatic breast cancer.