Background: The aim of this study was to evaluate the significance of spread through air spaces (STAS) in early lung adenocarcinomas after radical lobectomy and lymphadenectomy.
Methods: A total of 242 patients with lung adenocarcinomas less than 4 cm (8th pStage I) were selected from the lung cancer patients surgically treated from January, 2009 to September, 2011. Pathological review focused on STAS as well as histological subtypes, blood vessel & neural invasion, pathological tumor size etc. Recurrence or disease-free survival (DFS) and overall survival (OS) were compared between patients as stratified by STAS and tumor size.
Results: STAS was observed in 33.47% (81/242) patients, which was significantly correlated with histological predominant subtype (χ2=25.903, P=0.093×10-3) and differentiation grade (χ2=23.986, P=0.025×10-3). Patients with STAS (+) showed a comparable PFS (P=0.268) and OS rates (P=0.100) in all stage I cases, but a significant lower PFS (P=0.029) and OS (P=0.013) in tumors within 2< tumors ≤4 cm. Multivariate analysis revealed STAS to be an independent worse prognostic factor in lung adenocarcinomas within 2< tumors ≤4 cm, both for PFS (P=0.004) and OS (P=0.002), while no significant difference was found in patients with tumors ≤2 cm (PFS, P=0.537; OS, P=0.448), after adjusting by other clinicopathological parameters as age, gender, smoking etc.
Conclusions: Presence of STAS was a significant worse predictor for pStage I patients with lung adenocarcinoma >2 cm who underwent radical lobectomy, while it is not significant in patients with tumor ≤2 cm. These findings may be helpful in assessing postoperative therapy stratified by tumor size and STAS status.
Keywords: Lung adenocarcinoma; prognosis; recurrence; spread through air spaces (STAS); surgical treatment.