Tumor Spread through Air Spaces in Early-Stage Lung Adenocarcinoma: Surgical Implications and Patient Management...

Tumor spread through air spaces (STAS) is a recently recognized, clinically relevant invasive pattern in lung adenocarcinoma with important prognostic implications. Recognition of STAS has influenced ongoing discussions regarding the surgical management of non-small cell lung cancer. The International Association for the Study of Lung Cancer Staging Project recently recommended adopting STAS as a histologic T descriptor in the 9th edition of the tumor-node-metastasis (TNM) classification. Moving beyond its role as a morphological risk factor, recent studies suggest that STAS may serve not only as a prognostic marker but also as a potential indicator of divergent evolutionary trajectories shaped by underlying driver mutations. This review summarizes the morphological definitions of STAS, its observed impact on outcomes after sublobar resection, optimization of surgical margin distance, challenges in intraoperative diagnosis, differential prevalence according to genetic alterations, and proposed integration into the 9th edition of the TNM classification. Potential clinical considerations for risk stratification and patient management based on STAS are also discussed.