Han YB, Kim H, Mino-Kenudson M, et al. - In 1,869 resected non-small cell lung cancers (NSCLCs), researchers retrospectively evaluated the relationship between the degree of spread through air spaces (STAS) and clinicopathological features and patient outcomes. STAS was reported in 765 cases (40.9%) with 456 STAS I (24.4%) and 309 STAS II (16.5%). Patients with adenocarcinoma (ADC) (vs squamous cell carcinoma), pleural invasion, lymphovascular invasion, and/or higher pathologic stage were more likely to have STAS. Depending on the degree of STAS, significant differences in recurrence free survival (RFS), overall survival (OS), and lung cancer specific survival (LCSS) In ADC. According to multivariate analysis, STAS II was significantly associated with shorter RFS and LCSS in stage IA non-mucinous ADC. In both limited and radical resection groups, STAS II was an independent poor prognostic factor for recurrence.