AUTHOR=Zhao Dechang , Zhang Rusi , Yang Longjun , Huang Zirui , Lin Yongbin , Wen Yingsheng , Zhang Xuewen , Wang Gongming , Guo Guangran , Yu Xiangyang , Wang Weidong , Xi Kexing , Zhang Lanjun 

TITLE=The Independent Prognostic Effect of Lymph Node Dissection on Patients With Stage IA NSCLC With Different T Stages

JOURNAL=Frontiers in Surgery

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2021.798046

DOI=10.3389/fsurg.2021.798046

ISSN=2296-875X

ABSTRACT=Background: Currently, the extent of lymph node evaluation necessary for early-stage non-small-cell lung cancer (NSCLC) patients remains controversial according to the latest ESMO and NCCN guidelines. In this study, we aimed to evaluate the survival effect of different numbers of lymph nodes examined (LNE) and regions of lymph nodes removed (LNR) in stage IA NSCLC patients.
Method: All stage IA NSCLC patients undergoing lobectomy or bilobectomy were selected from the surveillance, epidemiology and end results (SEER) database. The number of LNE and LNR were stratified into 4 groups (0, 1-2, 3-8, ≥9 lymph nodes) and 3 groups (0, 1-3, ≥4 regions) respectively. Additionally, the survival curves of overall survival (OS) and cancer specific survival (CSS) were plotted and compared with the Kaplan-Meier method and log-rank test. Independent prognostic clinicopathological factors were evaluated via Cox proportional hazard regression and subgroup analysis.
Results: Totally, 12,490 stage IA NSCLC patients were enrolled in our study. Patients with ≥9 LNE and ≥4 LNR in both the T1b and T1c stages consistently demonstrated the significantly best OS and CSS outcomes. In the multivariate analysis, patients with ≥9 LNE consistently had a significantly better CSS (HR (95% CI): 0.539 (0.438-0.663)), and those with ≥4 LNR consistently had a significantly better OS (HR (95% CI): 0.678 (0.476-0.966)). Furthermore, ≥9 LNE and ≥4 LNR were associated with better survival in most subgroups.
Conclusion: This study demonstrated that ≥9 LNE and ≥4 LNR are highly recommended for stage IA2 and stage IA3 patients but optional for stage IA1 patients.