Consensus Definition of Stage III Non-Small-cell Lung Cancer Technical Resectability to Standardise Inclusion Criteria for Clinical Trials: a Multisocietal EORTC-Lung Cancer Group Collaboration

The decision regarding resectability in stage III non-small-cell lung cancer (NSCLC) is complex. To improve consistency in eligibility criteria in clinical trials, the European Organisation for Research and Treatment of Cancer (EORTC) initiated a Delphi study to establish a standardised definition of technical resectability for stage III NSCLC. 36 experts from the EORTC, European Respiratory Society, International Association for the Study of Lung Cancer, European Society for Radiotherapy and Oncology, European Thoracic Oncology Platform and International Breast Cancer Study Group, European Society of Thoracic Surgeons, and European Society of Pathology formulated 34 consensus statements on the definition of resectability. Consensus was defined as 75% agreement. After three Delphi rounds there was unanimous consensus that the decision on resectability should be made by experienced thoracic surgeons within the context of a multidisciplinary team. Initial assessments should include PET-CT, brain MRI, and invasive mediastinal staging. Stage IIIA was generally classified as resectable. Tumours with N2 involvement might be resectable depending on the nature of lymph node involvement (ie, single or multi-station, bulky or non-bulky, and invasive or non-invasive). Stage IIIB might be considered resectable, depending on lymph node characteristics: N2single mostly resectable; N2multi mostly unresectable; N2bulky mostly unresectable; and N2invasive or N3 unresectable. Stage IIIC was classified as unresectable. The proposed definitions aim to standardise inclusion criteria for clinical trials facilitating a more consistent evaluation of multimodal treatments for stage III NSCLC. Further data collection, especially on the nature of N2 disease, is needed to refine the definition.