Phase III Study of Mediastinal Lymph Node Dissection for Ground Glass Opacity–Dominant Lung Adenocarcinoma

Systematic mediastinal lymph node dissection (LND) or sampling is currently recommended for patients with early-stage non-small cell lung cancer. We aimed to investigate whether no mediastinal LND was noninferior to systematic LND in patients with ground glass opacity (GGO)-dominant invasive lung adenocarcinoma. We conducted a multicenter, open-label, phase III, noninferiority randomized controlled trial comparing systematic mediastinal LND versus no mediastinal LND in patients with GGO-dominant invasive lung adenocarcinoma, who were predicted to have no lymph node metastasis on the basis of criteria established in our previous trial. The primary end point was 3-year disease-free survival. An interim analysis was planned upon enrollment of 300 patients, with predefined termination criteria if no mediastinal lymph node metastasis is detected and life-threatening complications occur in the systematic LND arm. This trial is registered on ClinicalTrials.gov (ECTOP-1009, identifier: NCT04527419). Interim analysis of 302 patients revealed no lymph node metastasis in either study arm. The no LND arm had significantly reduced surgery duration (mean, 74 minutes v 109 minutes; P < .001), blood loss (mean, 44 mL v 82 mL; P = .033), and postoperative hospital stay (mean, 3.9 days v 4.5 days; P = .002). Complications observed in the systematic LND arm included chylothorax in one patient (0.7%) and intraoperative massive bleeding because of superior vena cava injury in one patient (0.7%). No lymphadenectomy-related complications occurred in the no LND arm. On the basis of interim findings and the principle of nonmaleficence, the trial should be terminated. Systematic mediastinal LND should no longer be recommended for patients with GGO-dominant lung adenocarcinoma.