Association Between N1 Nodal Assessment, Upstaging, and Survival in Resected Non-Small Cell Lung Cancer

We examined the rate of pathologic nodal upstaging and associated 3-year survival, stratified by extent of nodal assessment, in a cohort of cN0 non-small cell lung cancer (NSCLC) patients.

Adults who underwent pulmonary resection for cN0 NSCLC between 2021-2024 were identified from the STS GTSD. Rates of nodal upstaging and composite morbidity and mortality were examined, stratified by extent of nodal assessment. Vital status was derived via linkage to national administrative databases through 2024. Overall survival, stratified by extent of nodal assessment, was examined using Kaplan-Meier curves and risk adjusted via a Frailty Cox model, accounting for clustering within hospitals.

A total of 48,789 cN0 NSCLC patients were examined with an 11.2% (5,444/48,789) rate of nodal upstaging. Each additional N1 station evaluated at the time of surgery had a greater impact on nodal upstaging than each additional N2 station, with no effect on composite morbidity and mortality. For longitudinally-linked, pN0 patients (n=22,644), the 3-year overall survival improved incrementally with each additional N1 lymph node station examined. After risk-adjustment, evaluation of ≥2N1 stations was associated with lower mortality compared with evaluation of 1N1 station (aHR 0.86, 95% CI 0.76-0.98), with further benefit observed when ≥3N1 stations were examined (aHR 0.81, 95% CI 0.69-0.95). These associations were most pronounced when intrapulmonary nodes were evaluated.

In cN0 NSCLC, assessment of >1N1 nodal station, including station 12-14 lymph nodes, is associated with improved nodal upstaging. Among pN0 patients, more complete N1 assessment correlates with improved survival.