The addition of consolidation radiotherapy to first-line systemic anticancer therapy resulted in better local disease control and prolonged progression-free survival compared with systemic therapy alone in patients with synchronous oligometastaic non–small cell lung cancer (NSCLC) without an actionable genomic alteration, according to findings from the phase II SARON trial presented at ESMO Congress 2026 (Abstract 2613O).
Adverse effects from the addition of radiotherapy were considered acceptable, but the overall combination did not result in an overall survival benefit.
“Until now, there has been limited randomized evidence about the benefits of adding radiotherapy to the standard-of-care systemic treatment for patients with oligometastatic NSCLC. The SARON trial has provided important data in this context, demonstrating a significant improvement in progression-free survival without compromising quality of life. It is an exemplar of national collaboration, and these types of studies are crucial for informing personalised treatment approaches for patients,” said chief study investigator Fiona McDonald, MA, MBBS, MRCP, FRCR, MD, Consultant Thoracic Clinical Oncologist at The Royal Marsden NHS Foundation Trust and Leader of the Thoracic Radiotherapy Group at The Institute of Cancer Research.
Background and Study Methods
The multicenter, randomized phase II SARON trial randomly assigned patients with NSCLC and one to five metastases in up to three organs (n = 140) to receive first-line systemic anticancer therapy with or without radical radiotherapy to the lung primary and/or locoregional lymph nodes plus stereotactic ablative radiotherapy to the oligometastatic sites. In January 2020, the control arm was changed to include immunotherapy.
Patients were stratified by their systemic therapy, histology, N stage, number of metastases, brain metastases, and recruiting site.
The primary endpoint was overall survival and a major secondary endpoint was progression-free survival.
Key Findings
Patients were followed for a median of 37.4 months. The median overall survival was 31 months in the multimodal arm vs 28 months in the systemic therapy alone arm (hazard ratio [HR] = 0.99; 95% confidence interval [CI] = 0.63–1.55; P = .95). The median progression-free survival was 13.9 months with added radiotherapy and 8.9 months without, prolonging progression-free survival by 56% (HR = 0.64; 95% CI = 0.43–0.95; P = .03).
Cumulative rates of local failure within 12 months were 13% and 39.5% in the systemic therapy with radiation arm and the systemic therapy only arm, respectively (P < .01). Among patients with new distant metastasis, the rates of local failure within 12 months were 36.2% in the combination arm vs 32.3% in the systemic therapy only arm (P = .28).
The rate of grade 3 or higher adverse events was 28.6% in each arm, with six patients experiencing a grade 3 event that was possibly related to radiotherapy.
Quality-of-life measures were also similar in both arms.
DISCLOSURES: The SARON trial was funded by Cancer Research UK and sponsored by University College London (UCL). For full disclosures of the study authors, visit ctimeetingtech.com/esmo2026.
