Radiation therapy for oligometastatic non-small cell lung cancer

Interest has been increasing in the treatment of non-small cell lung cancer (NSCLC) patients with limited or oligometastatic disease. Surgery has historically been used to remove non-small cell lung cancer metastases, but recent developments including advanced radiotherapy planning and delivery techniques, often called stereotactic body radiotherapy (SBRT) or stereotactic ablative radiotherapy (SABR), has been associated with high rates of treated metastasis control. Therefore, given common comorbid disease, often precluding surgery, an increasing number of oligometastatic NSCLC patients are receiving radiation for ablation of all disease. Early results have reported favorable survival for some, with improved median survival, and approximately 25 % alive long term. Patients with fewer metastases, those treated to all known cancerous sites, and longer disease-free intervals tend to have better outcomes. While promising, better clinical criteria are needed to optimize patient selection. The biologic underpinnings of the oligometastatic state are beginning to be demonstrated with specific microRNAs being associated with limited or no progression both in human samples and murine models. Clinical trials are ongoing to improve the techniques used to deliver radiotherapy for NSCLC oligometastases. Ideally, randomized studies will need to be conducted to demonstrate the utility of these treatments suggested by the uncontrolled studies to date. In lieu of these, data presented here may help guide clinicians as to appropriate patient selection.