SBRT for oligoprogressive disease: using the evidence to maximise the benefits

The use of stereotactic body radiotherapy (SBRT) in oligometastatic disease is being studied across several primary tumour types and across the breadth of oligometastatic states; 1 Guckenberger M Lievens Y Bouma AB et al. Characterisation and classification of oligometastatic disease: a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation. Lancet Oncol. 2020; 21: e18-e28 Summary Full Text Full Text PDF PubMed Scopus (498) Google Scholar however, gathering evidence for the benefit of SBRT has been challenging. Previous studies have shown the effectiveness and safety of SBRT in patients with de-novo metachronous disease 2 Palma DA Olson R Harrow S et al. Stereotactic ablative radiotherapy for the comprehensive treatment of oligometastatic cancers: long-term results of the SABR-COMET phase II randomized trial. J Clin Oncol. 2020; 38: 2830-2838 Crossref PubMed Scopus (574) Google Scholar and synchronous oligometastatic non-small-cell lung cancer (NSCLC), 3 Gomez DR Blumenschein Jr, GR Lee JJ et al. Local consolidative therapy versus maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer without progression after first-line systemic therapy: a multicentre, randomised, controlled, phase 2 study. Lancet Oncol. 2016; 17: 1672-1682 Summary Full Text Full Text PDF PubMed Scopus (780) Google Scholar in the pre-immunotherapy era. However, not all studies of SBRT have shown positive results; for instance, the phase 2/3 NRG-BR002 study of SBRT in patients with de-novo oligometastatic breast cancer did not show an added benefit. 4 Chmura SJ Winter KA Woodward WA et al. NRG-BR002: a phase IIR/III trial of standard of care systemic therapy with or without stereotactic body radiotherapy (SBRT) and/or surgical resection (SR) for newly oligometastatic breast cancer (NCT02364557). Proc Am Soc Clin Oncol. 2022; 40 (abstr).1007 Google Scholar Standard-of-care systemic therapy with or without stereotactic body radiotherapy in patients with oligoprogressive breast cancer or non-small-cell lung cancer (Consolidative Use of Radiotherapy to Block [CURB] oligoprogression): an open-label, randomised, controlled, phase 2 studyThe trial showed that progression-free survival was increased in the SBRT plus standard-of-care group compared with standard of care only. Oligoprogression in patients with metastatic NSCLC could be effectively treated with SBRT plus standard of care, leading to more than a four-times increase in progression-free survival compared with standard of care only. By contrast, no benefit was observed in patients with oligoprogressive breast cancer. Further studies to validate these findings and understand the differential benefits are warranted. Full-Text PDF