Correlation Between Programmed Death Receptor-1 Expression in Tumor-Infiltrating Lymphocytes and Programmed Death...

Area of Science:

• Immunology
• Oncology
• Pathology

Background:

• The programmed death receptor-1 (PD-1) and programmed death ligand-1 (PD-L1) pathway inhibits T cell-mediated immune responses.
• Tumors exploit the PD-1/PD-L1 interaction to evade immune surveillance.
• While PD-1/PD-L1 correlation is known in advanced non-small cell lung carcinoma (NSCLC), its role in early stages is less understood.

Purpose of the Study:

• To investigate the correlation between PD-1 and PD-L1 expression in non-small cell lung carcinoma (NSCLC) tumor samples.
• To specifically analyze this correlation in early-stage (Stage I) NSCLC.

Main Methods:

• Retrospective analysis of whole tissue sections from NSCLC tumors.
• Immunohistochemistry was used to evaluate PD-1 expression in tumor-infiltrating lymphocytes (TILs) and PD-L1 expression in tumor cells (TCs) and immune cells (ICs).
• Scoring was based on the percentage of positive cells for PD-1 and PD-L1.

Main Results:

• PD-1 expression in TILs was detected in 91% of NSCLC cases.
• Strong correlations were found between elevated PD-1 in TILs and PD-L1 in TCs (P = .01) and ICs (P = .003).
• Negative PD-1 and PD-L1 expression showed a trend towards improved disease-specific survival in Stage I NSCLC patients.

Conclusions:

• PD-1 expression in TILs is significantly correlated with PD-L1 expression in both TCs and ICs in NSCLC.
• The absence of both PD-1 and PD-L1 expression may indicate a favorable prognosis, even in early disease stages.
• These findings highlight the potential of targeting the PD-1/PD-L1 axis in early-stage NSCLC.