Cancer cell-specific PD-L1 expression is a predictor of poor outcome in patients with locally advanced oral cavity squamous cell carcinoma
Details
Publication Year 2024-10-02,Volume 12,Issue #10,Page e009617
Journal Title
Journal for Immunotherapy of Cancer
Publication Type
Research article
Abstract
BACKGROUND: Locally advanced oral cavity squamous cell carcinoma (OCSCC) presents a significant clinical challenge despite being partially responsive to standard treatment modalities. This study investigates the prognostic implications of programmed death-ligand 1 (PD-L1) expression in these tumors, focusing on its association with treatment outcomes and the immune microenvironment. METHODS: We assessed tumor-infiltrating lymphocytes (TILs) in 132 patients with OCSCC to evaluate their impact on survival. Multiplex immunohistochemistry staining for CD3, CD68, CD11c, PD-L1, and P40 was used to explore correlations with clinical outcomes in patients with early-stage (n=22) and locally advanced (n=36) OCSCC. These initial findings were validated through differential gene expression analysis, gene set enrichment, and immune cell deconvolution in a The Cancer Genome Atlas cohort of 163 locally advanced OCSCC tumors. Additionally, single-cell RNA sequencing (scRNA-seq) on a smaller cohort (n=10) further characterized the PD-L1(hi) or PD-L1(lo) cancer cells in these tumors. RESULTS: Elevated PD-L1 expression was associated with poor outcomes in patients with locally advanced OCSCC undergoing standard adjuvant therapy, irrespective of "hot" or "cold" classification based on TILs assessment. PD-L1(hi) tumors exhibited an active immune response phenotype, enriched with M1 macrophages, CD8(+) T cells and T regulatory cells in the tumor microenvironment. Notably, the negative impact of PD-L1 expression on outcomes was primarily attributed to its expression by cancer cells, rather than immune cells. Furthermore, scRNA-seq revealed that immune interactions were not essential for PD-L1 upregulation in cancer cells, instead, complex regulatory networks were involved. Additionally, PD-L1(lo) locally advanced tumors exhibited more complex pathway enrichment and diverse T-cell populations compared with those in the early-stage. CONCLUSION: Our findings underscore the prognostic significance of PD-L1 expression in locally advanced OCSCC, and unveil the complex interplay between PD-L1 expression, immune responses, and molecular pathways in the tumor microenvironment. This study provides insights that may inform future therapeutic strategies, including the possibility of tailored immunotherapeutic approaches for patients with PD-L1(hi) locally advanced OCSCC.
Publisher
BMJ
Keywords
Humans; *B7-H1 Antigen/metabolism; *Mouth Neoplasms/pathology/immunology/metabolism/genetics; Male; Female; Middle Aged; *Tumor Microenvironment; *Lymphocytes, Tumor-Infiltrating/immunology/metabolism; Aged; Prognosis; Biomarkers, Tumor/metabolism; Carcinoma, Squamous Cell/immunology/metabolism/pathology/genetics; Adult; Squamous Cell Carcinoma of Head and; Neck/immunology/metabolism/genetics/pathology/mortality; Adjuvant; Head and Neck Cancer; Immune Checkpoint Inhibitor; Radiotherapy/Radioimmunotherapy; Tumor Microenvironment
Department(s)
Laboratory Research
Open Access at Publisher's Site
https://doi.org/10.1136/jitc-2024-009617
Terms of Use/Rights Notice
Refer to copyright notice on published article.


Creation Date: 2024-11-12 06:11:11
Last Modified: 2024-11-12 06:12:19

© 2024 The Walter and Eliza Hall Institute of Medical Research. Access to this website is subject to our Privacy Policy and Terms of Use

An error has occurred. This application may no longer respond until reloaded. Reload 🗙