WORLD JOURNAL OF ADVANCE
HEALTHCARE RESEARCH

Noor Wasfi Hassoon*, Professor Dr. Hadi Muhammad Ali Almosawi and Professor Dr. Ali Salih Baay

ABSTRACT

Background: Programmed death ligand-1 (PD-L1) is a 33 kDa type 1 transmembrane protein that suppresses the adaptive immune response. Its interaction with programmed death-1 (PD-1) receptor inhibits cytokine production and contributes to immune evasion by tumor cells, playing a significant role in the progression of lung cancer. Objective: This study aimed to evaluate PD-L1 expression in non-small cell lung cancer (NSCLC) patients and its correlation with histopathological grade, tumor type, patient age, and gender. Materials and Methods: A retrospective study with prospective continuation was conducted on 62 histologically diagnosed NSCLC cases over six months at the Babylon Training Center of Pathology. PD-L1 immunohistochemical expression was assessed and scored using the Tumor Proportion Score (TPS). Statistical correlations were analyzed between PD-L1 expression and patient age, gender, tumor type, and histopathological grade. Results: This study comprised 62 NSCLC patients, 77.4% of whom were men, with a mean age of 63.68 years. PD-L1 expression and cancer grade were strongly correlated with squamous cell carcinoma, where all PD-L1-positive patients were moderately or poorly differentiated (p = 0.02). No association was seen between gender and adenocarcinoma grade (p = 0.09). Among the 62 NSCLC cases, 43.5% exhibited PD-L1 positivity. A statistically significant correlation was observed between PD-L1 expression and both patient age and tumor grade, indicating higher expression in older patients and poorly differentiated tumors. Among the PD-L1 positive cases, 63.0% demonstrated low expression, while 37.0% showed high expression. However, TPS levels did not significantly correlate with any of the studied clinicopathological parameters. Conclusion: In NSCLC, PD-L1 expression was highly linked to worse differentiation. Age was significantly correlated, although gender and tumour histological subtype (SCC vs. adenocarcinoma) were not.