**5. Conclusions**

In conclusion, we retrospectively reviewed the clinical and pathological characteristics of patients with completely resected stage IIIA-N2 NSCLC, according to the eighth edition of the AJCC staging system. Tumor size <3 cm was the only independent factor for better OS and DFS. In addition, the VATS approach was also a good prognostic factor regarding OS rate. These findings may be helpful to identify patients with stage IIIA-N2 NSCLC eligible to surgical resection.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/9/5/1307/s1. Figure S1: Disease-free survival curves of patients stratified by tumor size. Table S1: Univariate analysis of factors associated with disease-free survival. Table S2: Multivariate analysis of factors associated with disease-free survival.

**Author Contributions:** Conceptualization, Chih-Yu Chen; Data curation, Wen-Chien Cheng and Wei-Chun Chen; Formal analysis, B.-R.W. and C.-H.C.; Methodology, C-H.C.; Software, Chih-Yu Chen; Supervision, T.-C.H. and C.-Y.T.; Validation, Chih-Yi Chen; Visualization, C-H.C.; Writing—original draft, Chih-Yu Chen; Writing—review & editing, W.-C.L. All authors have read and agreed to the published version of the manuscript.

**Acknowledgments:** The authors would like to thank the editor and reviewers for the editorial assistance and their valuable comments. This study is supported in part by the Taiwan Ministry of Health and Welfare Clinical Trial Center (MOHW109-TDU-B-212-114004).

**Conflicts of Interest:** The authors declare no conflict of interest.
