The presence of membranous immunopositivity of
programmed death-ligand 1 (PD-L1) in
tumors serves as a key determinant of response to
immune checkpoint inhibitors. However, there are very limited studies on the evaluation of the PD-L1
mRNA expression and immunopositivity and their correlation with therapeutic response and survival outcomes, especially in Indian
lung cancer patients. In this prospective study, conducted between 2017 and 2020, we collected biopsies and surgically resected
tumors from 173
lung cancer patients. PD-L1 immunopositivity and
mRNA expression were determined by immunohistochemistry using SP263 assay and qRT-PCR, respectively. PD-L1 expression was correlated with various clinicopathological variables, response to
therapy, and survival outcomes using appropriate statistical methods. The median age was 60 years (range 33-81 years) with the majority of patients being male (86.5%) and smokers (83%). Histologically, the majority of patients were
non-small cell lung cancer (89.4%) and of
squamous cell carcinoma histology (64.3%). PD-L1 immunopositivity in
tumor cells (
tumor proportion score (TPS) ≥ 1%) was detected in 37.6%, while high immunopositivity (TPS ≥ 50%) was detected in 16.8% of
lung cancer patients. Almost 76% of
lung cancer patients with PD-L1 TPS ≥ 50% belonged to PD-L1
mRNA high-expression group. PD-L1
mRNA expression and immunopositivity did not correlate with response to
therapy and survival outcomes. We conclude that PD-L1 immunopositivity and
mRNA expression do not seem to serve as a prognostic
biomarker for
lung cancer patients treated with
chemotherapy. More prospective studies should be planned to evaluate the predictive and prognostic relevance of PD-L1 expression in Indian
lung cancer patients being treated with
immune checkpoint inhibitors.