MA12.06 Tumor Spread through Air Spaces (STAS) in Lung Squamous Cell Cancer is an Independent Risk Factor: A Competing Risk Analysis

Abstract

Tumor spread through air spaces (STAS) is a recently recognized pattern of invasion in lung adenocarcinoma, however, the incidence of and prognostic importance of STAS have not yet been defined in squamous cell carcinoma (SCC). In a cohort of 445 patients with p-stage I-III lung SCC, cumulative incidence of recurrence and lung cancer-specific death (LCSD) was evaluated by competing risks analysis and overall survival (OS) by Cox models. 76% of patients were >65 years of age. 273 patients died during follow up, one third (91, 33.3%) died of lung cancer whereas two thirds died of competing events or unknown cause. STAS was present in 132 (30%). The cumulative incidence of any, distant, and locoregional recurrence as well as LCSD were significantly higher in patients with STAS compared to those without STAS (Figure), whereas there was no statistically significant difference in OS. STAS was an independent predictor for both recurrence and LCSD in multivariable analysis (p=0.034 and 0.016, respectively, Table). STAS was present in one third of resected lung SCC and it was an independent predictor of recurrence and LCSD, supporting our proposal that STAS is a clinically important pattern of invasion and not an artifact.View Large Image Figure ViewerDownload Hi-res image Download (PPT)