The effect of the extent of lymph node dissection for stage IA non-small-cell lung cancer on patient disease-free survival

Abstract

Background: Systematic LN dissection has been proposed as 1 of the important parts of the standard surgery for NSCLC for decades. However, controversy exists as to whether extensive LN dissection has benefit for early stage NSCLC patients. The aim of the present study was to investigate whether the extent of dissection affects the DFS of stage IA patients.

Patients and methods: The stations dissected and the LN obtained during operations from stage IA NSCLC patients were recorded and the patients were grouped according to the number of dissected LN (N), total stations (NS) and mediastinal stations (N2). The DFS curve of patients from each group were generated by the Kaplan-Meier method and compared with the log-rank test. The correlation between the patients' clinical features and N retrieval were also analyzed.

Results: A total of 203 stage IA NSCLC patients were grouped (N ≤ 10, 10 < N ≤ 20, and N > 20; NS ≥ 6 and NS < 6; N2 ≥ 3 and N2 < 3) and analyzed. Right-sided disease, tumor maximal diameter > 2 cm, and more NS or N2 dissected correlated with more retrieval of LN (P = .001, .003, < .001, < .001). The increase of N, NS, and N2 dissected were found to predict improved DFS (P = .001, .019, < .001), but there were no significant survival differences between the N ≤ 20 and N > 20 patients within the NS ≥ 6 subset (P = .140).

Conclusion: The dissection of more stations did increase the harvest of LN, which could achieve better survival for a stage IA NSCLC patient. The number of dissected (mediastinal) stations served as a more significant prognostic factor.