Segmentectomy vs Lobectomy for Clinical Stage IA Lung Adenocarcinoma With Spread Through Air Spaces.

BACKGROUND: This study aimed to investigate the prognosis after segmentectomy as compared with lobectomy for small-sized lung adenocarcinoma with spread through air spaces (STAS). METHODS: This retrospective study included 609 patients who underwent lobectomy or segmentectomy with lymph node dissection for clinical stage IA lung adenocarcinoma between April 2011 and March 2020 at Hiroshima University Hospital. Patient characteristics and prognosis after segmentectomy and lobectomy were investigated. RESULTS: STAS was detected in 293 patients (48.1%). The recurrence-free survival (RFS) rate was significantly worse with STAS-positive adenocarcinoma than with STAS-negative adenocarcinoma both in patients who underwent lobectomy (5-year RFS, 68.2% vs 90.2%; P < .001) and in patients who underwent segmentectomy (5-year RFS, 81.3% vs 93.0%; P = .003). Among the patients with STAS, there was no significant difference in RFS between patients who underwent lobectomy (5-year RFS, 68.2%) and those who underwent segmentectomy (5-year RFS, 81.3%; P = .225). In a multivariable analysis using propensity score to adjust clinical patient characteristics, segmentectomy was not found to be an independent prognostic factor of RFS (hazard ratio 0.732, P = .326) among patients with STAS. Among the patients with STAS, only 1 patient (1%) with insufficient resection margin (0.5 mm) had local recurrence and 1 patient (1%) with invasive mucinous adenocarcinoma had recurrence in preserved lobe after segmentectomy. CONCLUSIONS: Spread through air spaces was a poor prognostic factor in patients with clinical stage IA lung adenocarcinoma. Prognosis after segmentectomy was comparable with that of lobectomy in lung adenocarcinoma with STAS without increasing locoregional recurrence.