Bilateral Mediastinal Lymphadenectomy Is Associated With Potential Survival Advantages in Patients With Stage I Non-Small Cell Lung Cancer Who Undergo Lung Resection.

Purpose: The optimal lymphadenectomy approach for solid-dominant stage I non-small cell lung cancer (NSCLC) is controversial. We compared postlobectomy survival outcomes to elucidate.

Materials and methods: Patients diagnosed with solid-dominant stage I NSCLC between 2008 and 2015 were included and grouped according to the mode of lymphadenectomy. Disease-free survival (DFS) and overall survival (OS) were compared, and survival analysis was performed among the groups. Cox analysis was used to identify independent prognostic factors. Nomograms for survival prediction on the basis of the lymphadenectomy mode were constructed and internally calibrated. Propensity score matching (PSM) was used to account for potential confounders. Subgroup comparisons between bilateral mediastinal lymphadenectomy (BML), systematic nodal dissection (SND), lobe-specific nodal dissection (L-SND), and selected nodal sampling (SNS) were conducted.

Results: In total, 983 patients were included. The 5-year OS rates were 98.2%, 86.9%, 86.4%, and 82.8% (P = .006), and the 5-year DFS rates were 87.1%, 76.4%, 69.5%, and 70.9% (P = .008) in the BML, SND, L-SND, and SNS groups, respectively. Given PSM, patients who underwent BML had longer OS (hazard ratio [HR], 0.358 [95% CI, 0.127 to 1.008]; P = .052) and DFS (HR, 0.563 [95% CI, 0.295 to 1.074]; P = .081) than patients who underwent SND with marginal significance. Compared with L-SND and SNS, BML was associated with significantly improved OS (HR, 0.343 [95% CI, 0.123 to 0.958]; P = .041 and HR, 0.250 [95% CI, 0.088 to 0.709]; P = .009, respectively) and DFS (HR, 0.474 [95% CI, 0.258 to 0.868]; P = .016 and HR, 0.467 [95% CI, 0.232 to 0.938]; P = .032, respectively). Subgroup analyses demonstrated that in male patients and those whose tumors were larger or more advanced, BML was associated with significantly better OS and DFS than other types of lymphadenectomies.

Conclusion: BML may be associated with improved survival in patients with solid-dominant stage I NSCLC, and BML is recommended for such patients, especially those with large tumors or more advanced disease.