Stereotactic body radiation therapy: A good dance partner of oligometastatic non-small cell lung cancer to the sound of SINDAS study

Abstract

The European Organization for Research on Treatment of Cancer Research published a consensus statement to establish the key criteria to define oligometastatic disease (OMD). According to those criteria, all lesions (both primary and metastatic) should be amenable to radical intent treatment with acceptable toxicity. Several retrospective studies have shown that adding local ablative therapy to the treatment of OMD improves outcomes; however, due to the diverse selection criteria and treatment strategies used in those studies, it is difficult to compare directly results to draw definitive conclusions. In recent years, prospective phase II trials, such as the SABR-COMET and "Oligomez" trials, have shown that stereotactic body radiation therapy (SBRT) improves outcomes in patients with OMD. More recently, interim results of the randomised phase 3 SINDAS trial were reported at the annual meeting of the American Society of Clinical Oncology 2020 demonstrating that upfront SBRT added to systemic treatment with tyrosine kinase inhibitors yielded a significant benefit in both progression-free survival and overall survival in patients with epidermal growth factor receptor-mutant oligometastatic non-small cell lung cancer. In the present editorial, we review the definition and historical context of advanced non-small cell lung cancer with OMD. In addition, we review the scientific evidence for local ablative therapy and SBRT and discuss the results of recently published prospective studies. We also discuss in depth the results of the SINDAS study, including the strengths and weaknesses of the study and the barriers to extrapolating these results to routine clinical practice.

Keywords: Oligometastatic; Non-small cell lung cancer; Stereotactic body radiation therapy; SINDAS; Local ablative therapy; Epidermal growth factor receptor mutations; Epidermal growth factor receptor-mutated

Core Tip: In this editorial, we review the definitions and historical context of advanced non-small cell lung cancer with oligometastatic disease. We also review the scientific evidence for local ablative therapy and stereotactic body radiation therapy as well as the results of recently-published prospective studies. Finally, we provide an in-depth analysis of the interim results of the SINDAS trial, particularly its strengths and weaknesses, and the barriers to extrapolating these findings to real-life clinical practice.