Definition of Synchronous Oligometastatic Non–Small Cell Lung Cancer—A Consensus Report

Abstract

IntroductionImproved outcome has been shown in patients with synchronous oligometastatic (sOM) NSCLC when treated with radical intent. As a uniform definition of sOM NSCLC is lacking, we developed a definition and diagnostic criteria by a consensus process. MethodsA pan-European multidisciplinary consensus group was established. Consensus questions were built on the basis of current controversies, and definitions were extracted from a survey, cases and a systematic review. This statement was formulated during a consensus meeting. ResultsIt was determined that definition of sOM NSCLC is relevant when a radical treatment that may modify the disease course (leading to long-term disease control) is technically feasible for all tumor sites with acceptable toxicity. On the basis of the review, a maximum of five metastases and three organs was proposed. Mediastinal lymph node involvement was not counted as a metastatic site. Fludeoxyglucose F 18 positron emission tomography–computed tomography and brain imaging were considered mandatory. A dedicated liver magnetic resonance imaging scan was advised for a solitary liver metastasis, and thoracoscopy and biopsies of distant ipsilateral pleural sites were recommended for a solitary pleural metastasis. For mediastinal staging, fludeoxyglucose F 18 positron emission tomography–computed tomography was deemed the minimum requirement, with pathological confirmation recommended if this influences the treatment strategy. Biopsy of a solitary metastatic location was mandated unless the multidisciplinary team is of the opinion that the risks outweigh the benefits. ConclusionA multidisciplinary consensus statement on the definition and staging of sOM NSCLC has been formulated. This statement will help to standardize inclusion criteria in future clinical trials.