International Expert Consensus on Semantics of Multimodal Esophageal Cancer Treatment: Delphi Study

Background Recent developments in esophageal cancer treatment, including studies exploring active surveillance following chemoradiotherapy, have led to a need for clear terminology and definitions regarding different multimodal treatment options. Objective The aim of this study was to reach worldwide consensus on the definitions and semantics of multimodal esophageal cancer treatment. Methods In total, 72 experts working in the field of multimodal esophageal cancer treatment were invited to participate in this Delphi study. The study comprised three Delphi surveys sent out by email and one online meeting. Input for the Delphi survey consisted of terminology obtained from a systematic literature search. Participants were asked to respond to open questions and to indicate whether they agreed or disagreed with different statements. Consensus was reached when there was ≥75% agreement among respondents. Results Forty-nine of 72 invited experts (68.1%) participated in the first online Delphi survey, 45 (62.5%) in the second survey, 21 (46.7%) of 45 in the online meeting, and 39 (86.7%) of 45 in the final survey. Consensus on neoadjuvant and definitive chemoradiotherapy with or without surgery was reached for 27 of 31 items (87%). No consensus was reached on follow-up after treatment with definitive chemoradiotherapy. Conclusion(s) Consensus was reached on most statements regarding terminology and definitions of multimodal esophageal cancer treatment. Implementing uniform criteria facilitates comparison of studies and promotes international research collaborations.