Programmed death-ligand 1 expression in diffuse large B-cell lymphoma is associated with poor prognosis

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Programmed death-ligand 1 (PD-L1) expression is recognized for its prognostic implications in various cancers.
• Investigating PD-L1 expression in diffuse large B-cell lymphoma (DLBCL) is crucial for understanding its role in disease progression.

Purpose of the Study:

• To investigate the expression patterns of PD-L1 in DLBCL.
• To determine the association between PD-L1 expression and clinicopathological variables in DLBCL patients.

Main Methods:

• Analyzed tumor tissue from 75 DLBCL patients using immunohistochemistry with an anti-PD-L1 antibody (Clone 22C3).
• Assessed PD-L1 expression using Tumor Proportion Score (TPS) and Combined Positive Score (CPS).
• Correlated PD-L1 expression with gender, age, clinical stage, LDH levels, tumor location, therapy response, and survival outcomes.

Main Results:

• PD-L1 expression (TPS ≥1% or CPS ≥20) was observed in 23.2% and 33.3% of DLBCL cases, respectively.
• No significant differences in PD-L1 expression were found concerning subtypes (GCB vs. non-GCB), gender, age, stage, location, or therapy response.
• Elevated baseline lactate dehydrogenase (LDH) was associated with higher PD-L1 CPS (≥20).
• While overall survival did not differ significantly, event-free survival was notably shorter in PD-L1-positive cases (54 months) compared to PD-L1-negative cases (107 months).

Conclusions:

• PD-L1 expression serves as a significant predictor of event-free survival in DLBCL.
• PD-L1 positivity in DLBCL indicates a potentially poorer prognosis, highlighting its clinical relevance.