title: Spread through air spaces is a predictive factor of recurrence and a prognostic factor in stage I lung adenocarcinoma.
abstract: Spread through air spaces (STAS) is considered a prognosticator related to local recurrence. We assessed the prognostic impact of spread through air spaces and local recurrence in stage I lung adenocarcinoma.
  
  
  
  From July 2004 to November 2014, 877 lung cancer patients underwent surgery, of whom 318 with pathological stage I adenocarcinoma were reviewed. We investigated the characteristics of spread through air spaces and analysed the relationship between spread through air spaces and prognosis.
  
  
  
  The median follow-up was 30 months. Of the 318 patients, 47 (14.8%) had spread through air spaces. The patients with spread through air spaces were associated with male sex (P < 0.001), smoking (P < 0.001), solid nodules (P < 0.001), stage IB disease (P = 0.006), epidermal growth factor receptor mutation negativity (P < 0.001), and lymphovascular (P < 0.001) and pleural invasion (P = 0.001). Among the preoperative findings, spread through air spaces was significantly related to solid nodules on computed tomography. Local recurrence occurred in 11 of 47 (23.4%) cases with spread through air spaces and 10 of 271 (3.7%) cases without spread through air spaces (P < 0.01). Univariate analysis showed that the overall 5-year survival rates were 62.7 and 91.1% in cases with and without spread through air spaces, respectively (P < 0.01), and the recurrence-free 5-year survival rates were 54.4 and 87.8% in cases with and without spread through air spaces, respectively (P < 0.01). Multivariate analysis confirmed spread through air spaces as a significant prognosticator for overall survival and a predictive factor for recurrence after surgery.
  
  
  
  Among stage I lung adenocarcinoma patients, spread through air spaces was found frequently in the invasive cases and was closely related to poor prognosis and recurrence.
authors.affiliation: Department of Thoracic Surgery, Yamagata Prefectural Central Hospital, Yamagata, Japan sshiono@ypch.gr.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shiono
authors.affiliation: Department of Pathology, Yamagata Prefectural Central Hospital, Yamagata, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Yanagawa
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000209:etiology / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
keywords: Lung cancer; Lung cancer surgery; Lung pathology