*Article* **Prognostic Value of Tumor Size in Resected Stage IIIA-N2 Non-Small-Cell Lung Cancer**

**Chih-Yu Chen 1,2, Bing-Ru Wu 1,2, Chia-Hung Chen 1,2, Wen-Chien Cheng 1,2, Wei-Chun Chen 1,3,4, Wei-Chih Liao 1,2,4,\*, Chih-Yi Chen 5, Te-Chun Hsia 1,3,4 and Chih-Yen Tu 1,2**


Received: 24 March 2020; Accepted: 29 April 2020; Published: 1 May 2020

**Abstract:** The eighth edition of the American Joint Committee on Cancer (AJCC) staging system for lung cancer was introduced in 2017 and included major revisions, especially of stage III. For the subgroup stage IIIA-N2 non-small-cell lung cancer (NSCLC), surgical resection remains controversial due to heterogeneous disease entity. The aim of this study was to evaluate the clinicopathologic features and prognostic factors of patients with completely resected stage IIIA-N2 NSCLC. We retrospectively evaluated 77 consecutive patients with pathologic stage IIIA-N2 NSCLC (AJCC eighth edition) who underwent surgical resection with curative intent in China Medical University Hospital between 2006 and 2014. Survival analysis was conducted, using the Kaplan–Meier method. Prognostic factors predicting overall survival (OS) and disease-free survival (DFS) were analyzed, using log-rank tests and multivariate Cox proportional hazards models. Of the 77 patients with pathologic stage IIIA-N2 NSCLC examined, 35 (45.5%) were diagnosed before surgery and 42 (54.5%) were diagnosed unexpectedly during surgery. The mean age of patients was 59 years, and the mean length of follow-up was 38.1 months. The overall one-, three-, and five-year OS rates were 91.9%, 61.3%, and 33.5%, respectively. Multivariate analysis showed that tumor size <3 cm (hazards ratio (HR): 0.373, *p* = 0.003) and video-assisted thoracoscopic surgery (VATS) approach (HR: 0.383, *p* = 0.014) were significant predictors for improved OS. For patients with surgically treated, pathologic stage IIIA-N2 NSCLC, tumor size <3 cm and the VATS approach seemed to be associated with better prognosis.

**Keywords:** non-small-cell lung cancer; stage IIIA-N2; surgery
