Immune Infiltration and Survival Analysis in Lung Adenocarcinoma: Identifying Prognostic Cell Types

The tumor microenvironment (TME) plays a crucial role in the development and survival of neoplastic cells, with tumor-infiltrating leukocytes (TILs) constituting a significant component. This immune infiltrate exhibits a diverse composition of adaptive and innate immunological cell subtypes, with varying prognostic implications across different cancer types. Recent advancements in immunotherapy underscore the importance of evaluating TILs as potential biological identifiers, particularly in the context of novel treatment strategies. In lung adenocarcinoma, the most prevalent histological subtype of lung cancer, multiple immune cell types have been identified within the TME, influencing tumor classification, clinical outcomes, and patient survival. While prior research has demonstrated a correlation between tumor-infiltrating immune cells and the progression of lung adenocarcinoma, few studies have examined their prognostic implications comprehensively. Building upon our previous work, where we constructed a signature matrix (Verma, 2024b.) and evaluated the fractions of 14 immune cell types in TCGA-LUAD data and performed ESTIMATE analysis to assess immune infiltration, stromal infiltration, and tumor purity (Verma, 2024a.), in this study, we investigate the association between immune cell infiltration patterns and the overall survival and prognosis of TCGA-LUAD patients across different histological subtypes and stages. Our findings aim to elucidate the immune cell types positively or negatively impacting patient outcomes in lung adenocarcinoma and inform future therapeutic approaches.