Two Interventions on Pathologic Nodal Staging in a Population-Based Lung Cancer Resection Cohort

BACKGROUND Despite its prognostic importance, poor pathologic nodal staging of lung cancer prevails. We evaluated the impact of 2 interventions to improve pathologic nodal staging. METHODS We implemented a lymph node specimen collection kit to improve intraoperative lymph node collection (surgical intervention) and a novel gross dissection method for intrapulmonary node retrieval (pathology intervention) in nonrandomized stepped-wedge fashion, involving 12 hospitals and 7 pathology groups. We used standard statistical methods to compare surgical quality and survival of patients who had neither intervention (group 1), pathology intervention only (group 2), surgical intervention only (group 3), and both interventions (group 4). RESULTS Of 4019 patients from 2009 to 2021, 50%, 5%, 21%, and 24%, respectively, were in groups 1 to 4. Rates of nonexamination of lymph nodes were 11%, 9%, 0%, and 0% and rates of nonexamination of mediastinal lymph nodes were 29%, 35%, 2%, and 2%, respectively, in groups 1 to 4 (P < .0001). Rates of attainment of American College of Surgeons Operative Standard 5.8 were 22%, 29%, 72%, and 85%; and rates of International Association for the Study of Lung Cancer complete resection were 14%, 21%, 53%, and 61% (P < .0001). Compared with group 1, adjusted hazard ratios for death were as follows: group 2, 0.93 (95% CI, 0.76-1.15); group 3, 0.91 (0.78-1.03); and group 4, 0.75 (0.64-0.87). Compared with group 2, group 4 adjusted hazard ratio was 0.72 (0.570.91); compared with group 3, it was 0.83 (0.69-0.99). These relationships remained after exclusion of wedge resections. CONCLUSIONS Combining a lymph node collection kit with a novel gross dissection method significantly improved pathologic nodal evaluation and survival.