Association of PD-L1 Expression With Tertiary Lymphoid Structures and Prognosis in Oral Cancer

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Tertiary lymphoid structures (TLSs) are present in invasive malignancy regions.
• The prognostic role of TLSs in oral squamous cell carcinoma (OSCC) remains incompletely understood.
• Programmed death-ligand 1 (PD-L1) is a key immune checkpoint molecule implicated in cancer progression.

Purpose of the Study:

• To investigate the relationship between PD-L1 expression and TLSs in OSCC.
• To determine the combined prognostic significance of PD-L1 and TLSs in OSCC patients.
• To explore the potential functional heterogeneity of TLSs based on PD-L1 status.

Main Methods:

• Analysis of 280 oral squamous cell carcinoma (OSCC) cases.
• Immunohistochemical assessment of PD-L1 expression in tumor biopsies and surgical specimens.
• Immune cell staining in cases with identified TLSs.

Main Results:

• High PD-L1 expression combined with TLSs showed significantly improved overall survival (p < 0.05).
• Low PD-L1 expression coupled with TLSs was significantly associated with poorer overall survival (p < 0.05).
• These findings highlight a dichotomous prognostic impact of TLSs dependent on PD-L1 levels.

Conclusions:

• In OSCC, TLSs associated with high PD-L1 expression predict a favorable prognosis.
• Conversely, TLSs with low PD-L1 expression correlate with significantly worse outcomes.
• TLSs in OSCC may exhibit functional heterogeneity, influencing prognosis based on PD-L1 expression levels.