Narrative review of the prognostic significance of immune cells in the tumor microenvironment of stage I lung cancer

Abstract

: Current staging for lung cancer is primarily based on TNM staging, which is purely anatomical. This staging method has served an important purpose of stratifying patients into risk categories based on tumor physical characteristics including tumor size, nodal involvement and metastasis. Nonetheless, the TNM staging has its limitations. One such limitation is the fact that this staging method cannot prognostically discriminate within the same tumor stage. This issue may become relevant with the increasing number of stage I patients being detected as a result of lung cancer screening. As such, investigations for additional prognostic markers become important. The tumor immune microenvironment (IME), including infiltrating immune cells, cell surface markers of these infiltrating cells and of the tumor cells, and signaling proteins (specifically cytokines), could provide the opportunity to stratify patients with early-stage lung cancer based on prognosis (e.g., post-operative recurrence risk) and provide insight on therapeutic responses as well as therapeutic targets. Knowledge of the IME in cancers is important as it serves as a basis for research that attempts to study the possibility of employing the immune system to actively destroy cancer cells (i.e., cancer immunotherapy). This article aims to review recent findings as they relate to prognosticators in the IME of stage I lung cancer. 17 , a cell infiltration, OS, I–II CD8+ infiltration a cell showed a positive correlation with increased CD8+ infiltration in univariate (P=0.002, 95% CI: 0.217–0.714, HR: 0.393) and multivariate analyses (P=0.034, 95% CI: 0.053– 0.892. HR: 0.218). Similar findings were shown for OS in univariate analysis (P=0.044, 95% CI: 0.259–0.982, HR: multivariate analysis showed a trend between high CD8+ TILs and improved OS (P=0.070, 95% CI: 0.276–1.052, HR: 0.539) et the of cells in NSCLC