

Increasing the number of N1 LN examination might improve the long-term survival of T1-2N0 NSCLC patients. Compared with patients with 0–5 N1 LNs examined, patients with more than 5 N1 LNs examined had better OS ( P = 0.015) and had better DFS ( P = 0.015) if only a landmark 5-year follow-up was performed. Gender ( P = 0.006), age ( P = 0.031), tumor size ( P = 0.001), differentiation degree ( P = 0.001), vascular invasion ( P = 0.034), and number of N1 LNs examined ( P = 0.007) were independent prognostic factors of disease-free survival. Sex ( P = 0.004), age ( P < 0.001), tumor size ( P = 0.004), differentiation degree ( P = 0.001), and number of N1 LNs examined ( P = 0.008) were independent prognostic factors of overall survival. The median number of resected N1 LNs was 8.

The Kaplan-Meier method and Cox regression model were used to identify survival and prognostic factors. Pathology records were reviewed for the number of LNs examined. The data of patients who underwent radical lobectomy and were confirmed as having non-metastatic LNs from January 2008 to March 2018 were retrospectively screened. In this study, we aimed to confirm the significance of N1 LNs in long-term survival for stage IA–IIA NSCLC patients and to find the minimum number of LN to examine. To date, the role of hilar and intrapulmonary (N1) station LNs has not been fully appreciated. For patients without LN metastasis, the main role of thorough LN examination is accurate staging, which weakens the effect of staging migration. The examination of lymph nodes (LNs) plays an important role in the nodal staging of non-small cell lung cancer (NSCLC).
