Abstract
INTRODUCTION: The American College of Surgeons Oncology Group Z0030 found no survival difference between patients with early stage NSCLC who had mediastinal nodal dissection or systematic sampling. However, a meta-analysis of 1980 patients in five randomized controlled trials from 1989 to 2007 associated better survival with nodal dissection. We tested the survival impact of the extent of nodal dissection in curative-intent resections for early stage NSCLC in a population-based observational cohort. METHODS: Resections for clinical T1 or T2, N0 or nonhilar N1, M0 NSCLC in four contiguous United States Hospital Referral Regions from 2009 to 2019 were categorized into mediastinal nodal dissection, systematic sampling, and "neither" on the basis of of the evaluation of lymph node stations. We compared demographic and clinical characteristics, perioperative complication rates, and survival after assessing statistical interactions and confounding. RESULTS: Of the 1942 eligible patients, 18% had nodal dissection, 6% had systematic sampling, and 75% had an intraoperative nodal evaluation that met neither standard. In teaching hospitals, nodal dissection was associated with a lower hazard of death than "neither" resections (0.57 [95% confidence interval: 0.41-0.79]) but not systematic sampling (0.74 [0.40-1.37]) after adjusting for multiple comparisons. There was no significant difference in hazard ratios at nonteaching institutions (p > 0.3 for all comparisons). Perioperative complication rates were not significantly worse after mediastinal nodal dissection or systematic sampling, compared with "neither," (p > 0.1 for all comparisons). CONCLUSIONS: In teaching institutions, mediastinal nodal dissection was associated with superior survival over less-comprehensive pathologic nodal staging. There was no survival difference between teaching and nonteaching institutions, a finding that warrants further investigation.