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

Purpose: 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.

Methods: 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).

Results: 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 109 minutes; < .001), blood loss (mean, 44 mL 82 mL; = .033), and postoperative hospital stay (mean, 3.9 days 4.5 days; = .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.

Conclusion: 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.