Station 4L lymph nodes are located in a technically challenging area near the aortic arch, left pulmonary artery, thoracic duct, and left recurrent laryngeal nerve. Dissection may improve nodal staging but may also increase operative complexity and complications. This study will evaluate whether station 4L dissection can be omitted without compromising long-term outcomes in patients with early-stage left-sided invasive non-small cell lung cancer.
Eligible participants will undergo complete resection by segmentectomy or lobectomy and systematic mediastinal lymph node dissection. After intraoperative frozen-section confirmation of invasive non-small cell lung cancer, participants will be randomized in a 1:1 ratio to station 4L lymph node dissection or no station 4L dissection. Randomization is stratified by tumor lobe. The planned enrollment is 384 participants, including 258 with left upper lobe tumors and 126 with left lower lobe tumors.
Participants will be followed every 6 months for 3 years after surgery. The primary comparison is 3-year disease-free survival. Secondary assessments include 3-year overall survival, surgery-related complications within 30 days, all-cause mortality within 90 days, and the frequency of station 4L nodal metastasis among participants assigned to station 4L dissection.
