An international and multidisciplinary EORTC survey on resectability of stage III non-small cell lung cancer

Introduction: The EORTC-Lung Cancer Group initiated a Delphi consensus process to establish a consensual definition of resectable stage III non-small cell lung cancer (NSCLC) for the use in clinical trials, including a systematic review, survey, and review of clinical cases. Here, the survey results are presented, aimed to identify areas of controversy. Methods: A survey was distributed among the members of six international organizations related to lung cancer. Respondents were interrogated on the resectability (not limited to the technical resectability) of all stage III NSCLC TNM-subsets (8th edition). Additionally, four N2-subdivisions were used. The threshold for agreement was 75%. Answers with "yes" were considered upfront resectable. "Yes" and "maybe" were grouped together and considered potentially resectable. Answers with "no" were considered unresectable. Results: 558 responses were collected from thoracic surgeons (38%), radiation oncologists (27%), medical oncologists (17%), pulmonologists (14%), and others (4%). Most worked in a specialized center (80%), had >5 years of experience (80%), were European (76%), male (73%), and treated >20 patients with stage III NSCLC annually (77%). Agreement was found in 26 (70%) out of 37 TNM-subsets: 9 (24%) were considered (potentially) resectable, and 17 (46%) unresectable. There was no agreement for 11 (30%) TNM-subsets: smaller tumors with N2-multistation, larger tumors with N2-single station, and invasive T4-tumors with maximum N2-single station involvement. Conclusions: This international and multidisciplinary survey showed agreement on the resectability for the majority of stage III NSCLC TNM-subsets, but also identified several TNM-subsets for which no agreement was found.