Real-World Prevalence of PD-L1 Expression Among Tumor Samples From Patients With Non-Small-Cell Lung Cancer

Area of Science:

• Oncology
• Immunotherapy
• Cancer Biomarkers

Background:

• Non-small-cell lung cancer (NSCLC) treatment often relies on immunotherapy targeting programmed cell death ligand 1 (PD-L1).
• PD-L1 expression levels, particularly a tumor proportion score (TPS) of ≥ 50%, are critical for determining patient eligibility for specific immunotherapies.
• Understanding the prevalence of high PD-L1 expression in diverse populations is essential for treatment planning and resource allocation.

Purpose of the Study:

• To determine the prevalence of non-small-cell lung cancer (NSCLC) with a high programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS) of ≥ 50% in a Brazilian cohort.
• To compare these findings with existing data from clinical trials and international databases.
• To identify factors associated with PD-L1 expression in Brazilian NSCLC patients.

Main Methods:

• A retrospective, cross-sectional study involving 1512 NSCLC patients from 5 laboratories in Brazil.
• PD-L1 expression was assessed using immunohistochemistry and collected from pathology reports.
• Statistical analyses included frequency distributions and Pearson's chi-squared test, with significance set at P < .05.

Main Results:

• The study included 1512 patients with a median age of 66 years; 56.02% were male and 58.04% had adenocarcinoma.
• Overall, 17.83% of patients had a PD-L1 TPS of ≥ 50%.
• Histologic type and testing laboratory were associated with PD-L1 expression levels.

Conclusions:

• The prevalence of high PD-L1 expression (≥ 50% TPS) in Brazilian NSCLC patients was lower than reported internationally.
• This lower prevalence may reduce the number of patients eligible for PD-1/PD-L1 inhibitor monotherapy.
• Further research is needed to understand regional variations in PD-L1 expression and its clinical implications.