Relationship between clinicopathologic characteristics and spread through air spaces in resected lung adenocarcinoma and squamous cell carcinoma cases

Abstract

<b>Introduction:</b> Spread through air spaces (STAS) has been defined as a new invasion pattern and a poor prognostic factor in resected lung adenocarcinoma and squamous cell carcinoma since 2015, though some considers it to be just an artifact caused by surgical and/or certain pathological procedures.&nbsp;This study aims to make a contribution in junction with this controversy. <b>Methods:</b> We analyzed 273 surgically resected lung adenocarcinoma and squamous cell carcinoma patients in terms of some variables such as age, sex, smoking status, histological subtypes, resection types, invasion patterns, pathological T, N categories, history of tru-cut biopsy, diameter of tumor, genetic mutations, and PD-L1 expression. <b>Results:</b> Out of all patients under investigation, STAS is observed in some 92 cases (33.7%). STAS positivity was more frequent and statistically significant in adenocarcinoma subtype than in squamous cell carcinoma (41.3% and 20.8% respectively) (p&lt;0.001). STAS was found to be more frequent in solid or micropapillary subtypes, the higher N-category, and the presence of lymphovascular and pleural invasions (p&lt;0.05). No relationship between other parameters and the existence of STAS was observed. <b>Conclusion:</b> As a result, STAS might be associated with too many pathologic characteristics that have aggressive behavior to regard it as “just an artifact.” As our study indicates, STAS is in vivo phenomenon, rather than the product of diagnostic procedures.