Neutrophil-related signature characterizes immune landscape and predicts prognosis of esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a globally prevalent malignancy, and neutrophils play a dual role in its progression and antitumor responses. This study aimed to investigate the prognostic significance of neutrophil-related genes (NRGs) and their potential in defining ESCC molecular subtypes. We identified differentially expressed genes (DEGs) and used univariate Cox analysis, followed by LASSO and multivariate Cox regression, to establish a five-gene prognostic signature. The model's predictive performance was confirmed in an external validation cohort. To validate this, we performed qPCR to investigate the expression patterns of the five biomarkers, and the results were completely consistent with our data mining findings. Additionally, we performed consensus clustering to identify distinct molecular subtypes and assessed their characteristics through functional enrichment and immune microenvironment analyses. The prognostic model demonstrated robust predictive power. Patients with a high NRG score had significantly worse survival outcomes and a more complex immune microenvironment. Our analysis also revealed two distinct ESCC subtypes, Cluster 1 and Cluster 2, with Cluster 1 showing higher expression of immune checkpoints and significant differences in functional enrichment and immune microenvironment composition. In conclusion, NRGs serve as promising prognostic biomarkers in ESCC, providing insights into distinct molecular subtypes with clinical implications for personalized therapy. These findings underscore the need for further research on NRGs to advance our understanding of ESCC biology.