Spread through air spaces is a poor prognostic indicator in patients undergoing lobectomy for lung cancer: A systematic review and meta-analysis

Abstract Background: Previous studies have confirmed the poor prognostic value of spread through air spaces (STAS) in patients undergoing limited resection for lung cancer. Nevertheless, its prognostic value remains controversial in patients undergoing lobectomy. Consequently, we aim to systematically and comprehensively evaluate the prognosis of patients with STAS undergoing lobectomy for lung cancer. Methods: An extensive search of literature databases was conducted. Recurrence-free survival (RFS) and overall survival (OS) were compared between patients with or without STAS undergoing lobectomy. In addition, results of the limited resection were also evaluated and presented. Results: 5 studies with 1531 patients reported the outcomes of lobectomy and 4 studies including 505 patients evaluated the survival of limited resection. In patients undergoing lobectomy, STAS was associated with significantly worse survival than non-STAS, including both RFS (HR=1.700; 95% CI: 1.265–2.283; P＜0.001; P for heterogeneity=0.637; I2=0.0%) and OS (HR=2.620; 95% CI: 1.138–6.031; P=0.024; P for heterogeneity=0.128; I2=51.4%). STAS was also correlated with shorter RFS (HR=3.434, 95%CI 2.173 to 5.428; P＜0.001; P for heterogeneity=0.828, I2=0.0%) and OS (HR=3.494, 95%CI 2.128 to 5.736; P＜0.001; P for heterogeneity=0.501, I2=0.0%) in limited resection. Conclusions: STAS is a poor prognostic indicator in patients undergoing lobectomy for lung cancer.