Prospective evaluation of radical surgery for adenocarcinoma of oesophagogastric junction: real-world insights from the CLAEG study

Background: The optimal surgical strategy for adenocarcinoma of oesophagogastric junction (AEG) remains debated, particularly regarding lymphadenectomy extent, gastrectomy type and surgical approach, with real-world prospective evidence being scarce. Objective: To map lymph node metastasis (LNM) patterns and assess surgical outcomes in a large multicentre cohort of patients with AEG undergoing radical resection. Design: The Chinese League of Adenocarcinoma of Esophagogastric Junction (CLAEG) registry, initiated in 2022 across 44 high-volume Chinese centres, prospectively enrolled AEG patients. This analysis included 2044 radical resections, with LNM assessed by station, stratified by Siewert type and neoadjuvant therapy. Surgical outcomes were compared between total versus proximal gastrectomy and laparoscopic versus open resection. Results: Most tumours were Siewert type II (64.6%) or III (33.4%). LNM was substantially higher in abdominal than mediastinal stations; category-1 nodes (metastasis, >10%) comprised stations 1, 2, 3, 4, 7, 8a, 9 and 11p. The LNM rates for mediastinal stations were 2.77% (No. 110), 0.71% (No. 111) and 0.68% (No. 112). Patients who received neoadjuvant therapy had lower LNM rates, indicating nodal downstaging. Among those undergoing gastrectomy, patients who underwent total gastrectomy had a lower postoperative complication rate than those who underwent proximal gastrectomy (14.8% vs 21.0%; p=0.001) and achieved more extensive lymphadenectomy. Compared with open surgery, patients who underwent laparoscopic resection experienced faster postoperative recovery without higher complication rates (16.5% vs 17.3%). No perioperative mortality occurred. Conclusion: The CLAEG study shows that abdominal lymphadenectomy should be prioritised in AEG, with neoadjuvant therapy, total gastrectomy and laparoscopy associated with favourable short-term outcomes.