The Prevalence of Programmed Death Ligand-1 (PD-L1) Expression in Non-Small Cell Lung Cancer: An Experience From Tertiary Care Hospital.

Background: The prevalence of programmed cell death ligand-1(PD-L1) expression in non-small cell lung cancer (NSCLC) within unselected populations remains a research topic, though PD-L1 expression is important in guiding treatment decisions.

Objectives: The study objective was to ascertain the prevalence of PD-L1 expression in patients of NSCLC and its association with clinicopathological characteristics and other gene mutations.

Methods: Samples from patients with NSCLCs were analyzed in the study to determine the expression of PD-L1 through immunohistochemistry (IHC) using rabbit anti-human PDL-1/CD274 monoclonal antibody. Correlation analysis was done using Pearson's correlation coefficient (r). The study analyzed the association between PD-L1 expression and clinicopathological features.

Results: A total of 245 consecutive patients (154 men with 62.9%) with NSCLCs were subjected to PD-L1 testing, and 30.6% (n=75) were identified to be positive. It was twice as prevalent in men than women, with 154 men and 91 females, respectively. The PD-L1 expression failed to demonstrate any statistical significance with age, gender, smoking status, type of materials, location of biopsy, Eastern Cooperative Oncology Group Performance Status, and Epidermal Growth Factor Receptor mutation. High PD-L1 expression with tumor proportion score (TPS ≥ 50) was observed in 38.8% of patients, and it was more prevalent in female patients 29 (38.7%), smokers 59 (78.7%), stage IV tumors 44 (58.7%), and stage III tumors 28 (37.3%).

Conclusions: Our study in Kerala showed PD-L1 expression in NSCLC patients, correlated with clinicopathologic factors. Males, COPD, ALK+, and advanced-stage tumors had higher expression. Females, smokers, poorly differentiated tumors, and stage IV tumors had high PD-L1.