Clinical stage-specific prognostic impact of adequate lymphadenectomy in early-stage lung cancer.

Abstract

Objectives: To assess the prognostic impact of adequate lymphadenectomy and determine the optimal nodal assessment for different clinical stages of lung cancer.

Methods: We retrospectively reviewed 1214 patients with clinical stage I-III non-small cell lung cancer who had preoperative positron emission tomography/computed tomography and curative surgery (2006-2017). Patients were categorized based on whether they had adequate (R0) or inadequate lymphadenectomy [R(un)]. Propensity score matching was conducted to minimize bias. Primary end points were recurrence-free survival (RFS), overall survival (OS), and cancer-specific survival. Secondary end points included outcomes stratified by clinical stages.

Results: Multivariate Cox analysis identified preoperative carcinoembryonic antigen level, tumour size, uptake of tumour on positron emission tomography/computed tomography, R(un) [hazard ratio (HR) = 2.16; P < 0.001), angiolymphatic invasion, lymph node involvement and postoperative adjuvant therapy as independent predictors of RFS. The matched cohort included 440 R0 and 440 R(un) patients, with a median follow-up of 94 months. Significant differences were found in 10-year RFS (77.2% vs 61.3%, P < 0.001), OS (75.8% vs 64.3%, P < 0.001) and cancer-specific survival (83.8% vs 74.2%, P < 0.001). Despite longer operative time for R0 (210 vs 195 min, P = 0.008), perioperative complications, hospital stay length and blood loss were similar. Subgroup analysis showed R(un) as an independent predictor of RFS in clinical stages IA3 (HR = 2.53, P = 0.001), IB (HR = 1.71, P = 0.046), and II (HR = 2.44, P < 0.001), but not in IA1 or IA2. R0 had significantly better RFS than R(un) in matched cohort of stages IA3 (P = 0.003), IB (P = 0.001) and II (P = 0.001).

Conclusions: Adequate lymph node assessment improves prognosis in patients with clinical stages ≥ IA3. A uniform nodal assessment approach should be reconsidered for different clinical stages.