Invasive mediastinal staging for resected non-small cell lung cancer in a population-based cohort

Objectives: Invasive mediastinal nodal staging is recommended before curative-intent resection in patients with non-small cell lung cancer deemed at risk for mediastinal lymph node involvement. We evaluated the use and survival effect of preoperative invasive mediastinal nodal staging in a population-based non-small cell lung cancer cohort. Methods: We analyzed all curative-intent resections for non-small cell lung cancer from 2009 to 2018 in 11 hospitals in 4 contiguous Dartmouth Hospital Referral Regions, comparing patients who did not have invasive mediastinal nodal staging with those who did. Results: Preoperative invasive nodal staging was used in 22% of 2916 patients, including mediastinoscopy only in 13%, minimally invasive procedures only in 6%, and both approaches in 3%. Sixty-three percent of patients at risk for nodal disease (tumor size >= 3.0 cm/T2-T4; N1-N3 by computed tomography or positron-emission tomography-computerized tomography criterion) did not undergo invasive staging; among those who did not have invasive testing, 47% had at least 1 of the 3 clinical indications. Mediastinoscopy yielded a median of 3 lymph nodes and 2 nodal stations; 17% of mediastinoscopies and 31% of endobronchial ultrasound procedures yielded no lymph node material. Patients not invasively staged were more likely to have no nodes (6% vs 2%; P<.0001) and no mediastinal nodes (20% vs 11%; P<.0001) examined at surgery. Invasive staging was associated with significantly better survival (P = .0157). Conclusions: More than a decade after the 2001 American College of Surgeons Patient Care Evaluation report, preoperative invasive nodal staging remains underused and of variable quality, but was associated with survival benefit in high-risk patients.