Stereotactic ablative radiotherapy for oligometastatic breast cancer: A systematic review and meta-analysis (SABRINA)
In brief
SABR achieves 91% two-year survival in de novo oligometastatic breast cancer
In a meta-analysis of 1,577 patients, stereotactic ablative radiotherapy gave 92% local control at one year and 91% overall survival at two years for newly diagnosed oligometastatic disease, versus only 66% survival for oligoprogressive cases. Toxicity was rare (about 1.5% grade 3+ events), but randomized data are still inconclusive, underscoring the need for trials that separate these disease states.
- Journal
- Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology (Q1)
- Published
- 20 September 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Gustavo A Viani, Ana Carolina Hamamura, Caio Viani Arruda, Carlos E Cardoso, Helio A Salmon, Gustavo O Amaral
- PMID
- 42764105
- DOI
- 10.1016/j.radonc.2026.111789
Why clinicians should know about it
- Picked for Radiation Oncology (paper of the day, 22 September 2026): SABR for oligometastatic breast cancer meta‑analysis
- Picked for Radiology, Radiation Oncology, Nuclear Medicine, Medical Physics and Imaging (paper of the day, 21 September 2026): SABR achieves durable local control with few adverse events
Abstract
OBJECTIVE: Stereotactic ablative radiotherapy (SABR) is increasingly used for oligometastatic breast cancer, but it is unclear in whom local ablation translates into systemic benefit. We compared de novo oligometastatic (OM) with oligoprogressive (OP) disease and synthesised randomised evidence. MATERIALS AND METHODS: PubMed, EMBASE, Cochrane CENTRAL and ClinicalTrials.gov were searched through March 2026. Endpoints were local control (LC), progression-free survival (PFS), overall survival (OS), time to next systemic therapy (TTNS) and grade 3 or higher adverse events. Proportions were pooled by random-effects models, adverse events by a binomial-normal model accommodating zero-event studies, and trials separately. RESULTS: Twenty-five cohorts (1,577 patients; 2,211 lesions) were included. Pooled LC was 92.5 % (95 % CI 90.4-94.2) at one year and 84.6 % (81.1-87.6) at two years, with no association with BED10. At two years, PFS was 43.1 % (34.4-52.2) and OS 85.8 % (76.0-92.0). Outcomes were consistently superior in de novo OM than in OP: LC 95.7 % versus 88.9 % (p = 0.001), PFS 50.9 % versus 30.9 % (p = 0.003), OS 91.0 % versus 65.8 % (p = 0.002), and TTNS 18.5 versus 11.3 months. Within OP, lesion number was independently associated with TTNS (adjusted HR 1.77 per lesion). Across four randomised trials the pooled hazard ratio for PFS was 0.73 (0.53-1.00; p = 0.053). Grade 3 or higher adverse events occurred in 21 of 1,366 patients (1.50 %; 0.74-2.28). CONCLUSIONS: SABR achieves durable local control with few treatment-related adverse events in all clinical contexts. Clinical context, rather than dose or metastatic site, determines whether that local effect translates into systemic benefit. Randomised evidence neither establishes nor excludes a benefit; trials stratified by oligometastatic state are required.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.