Lymph node sampling and survival in non-small-cell lung cancer: a 10-year Danish cohort study

OBJECTIVES: To investigate patterns of lymph node sampling and the potential impact on overall survival regarding adherence to selected intraoperative lymph node sampling guidelines. Additionally, we aimed to identify variables associated with guideline adherence and nodal upstaging. METHODS: A retrospective cohort study was conducted of patients undergoing anatomical lung resection for non-small cell lung cancer (clinical T1-4, N0 disease) from 2012 to 2021 identified through the Danish Lung Cancer Registry. Intraoperative lymph node sampling guidelines according to The National Comprehensive Cancer Network (NCCN) were selected. Missing data were imputed and propensity-score-matched by guideline adherence. Survival outcomes were analysed using Kaplan-Meier curves and log-rank test. Logistic and Cox regression assessed factors associated with survival, guideline adherence and nodal upstaging. RESULTS: A total of 6615 patients were included, 5670 remained after propensity-score-matched. Adherence to the NCCN guidelines did not impact overall survival (log-rank P-value = 0.31) or nodal upstaging (P-value = 0.26). No patient or tumour characteristics were significantly associated with guideline compliance. Factors associated with higher likelihood of upstaging included higher clinical T stage, histopathology, younger age, open surgery and type of resection. CONCLUSIONS: In this cohort, intraoperative lymph node sampling in adherence with the selected NCCN guidelines did not impact survival or nodal upstaging rates.