Spread Through Air Spaces is an Independent Predictor of Recurrence in Stage III (N2) Lung Adenocarcinoma

Objectives: Spread through air space (STAS) is recognized as a pattern of invasion in lung adenocarcinoma and has been reported to be a predictor of recurrence and survival in patients with early-stage lung adenocarcinoma. However, this parameter has not been studied well in stage III (N2) lung adenocarcinoma. In this study, we evaluated the association between STAS invasion patterns and recurrence and survival in stage III (N2) lung adenocarcinoma.

Methods: We retrospectively reviewed data from 76 patients at University of Tokyo with stage III (N2) lung adenocarcinoma who underwent surgery from August 1998 to December 2013. Statistical analysis was performed to determine the impact of STAS invasion clinicopathological features and clarify the relationship between this pattern of invasion and survival.

Results: Tumour STAS was observed in 46 of 76 patients (60.5%) and was significantly associated with the presence of lymphatic invasion (P < 0.001), papillary components (P < 0.001) and micropapillary components (P < 0.001). STAS was also significantly associated with recurrence (5-year recurrence-free probability: 19.0% vs 46.1%, P < 0.05). Univariate analyses showed that STAS was a significant risk factor for recurrence (hazard ratio 1.94, 95% confidence interval 1.07-3.51; P = 0.029).

Conclusions: The presence of STAS invasion pattern is a significant risk factor for recurrence in stage III (N2) lung adenocarcinoma.