Surgical approach in oligometastatic non-small cell lung cancer

The vast majority of lung cancer (80%) are non-small cell lung cancer (NSCLC) presenting in huge proportion of patients in a metastatic stage at the time of diagnosis with an overall survival (OS) of only 6 months. Standard treatment at this stage involves systemic platinum based chemotherapy improving the OS for only few months. For the vast majority of patients disease progression occurs and cure cannot achieved. An exception to this general rule is represented by patients with a limited number of metastasis (approximately 7% of patients with metastatic NSCLC): in 1995 Hellman and Weichselbaum introduced the term "oligometastatic" for a selected group of patients with metastatic disease. Several retrospective studies have been published and documented an improved outcome in patients managed surgically. The purpose of this narrative review is to gather all relevant information and present the various clinicopathological and generic aspects of diagnosis, management strategies and prognostic factors in patients with oligometastatic NSCLC. The key for long term survival includes radical treatment of the primary NSCLC, single organ site with either synchronous or metachronous presentation, a disease free interval to be as long as possible and the absence of intrathoracic lymph node spread (N0). A more accurate staging with combination of FDG-PET and CT scan can have on impact on the survival rates due to an increased accuracy in mediastinal staging and in the diagnosis of distant metastasis. No randomized data but only retrospective series are available to date to address this topic: in the future, additional prospective studies will be necessary to provide robust evidence to support the surgical resection as treatment of oligometastatic NSCLC.