Study of Programmed Death Ligand 1 and EGFR/HER2 Expression in Non-Small-Cell Lung Carcinoma With a Clinicopathological Spectrum

Non-small-cell lung carcinoma (NSCLC) is a disease characterized by the upregulation of programmed death ligand 1 (PD-L1) along with alterations in epidermal growth factor receptor (EGFR) and HER2-neu (HER2) amplification in addition to EGFR mutation. In the present study, the expression of PD-L1 and EGFR and HER2-neu in NSCLC was studied and their expression in relation to various clinicopathological parameters was analysed. We studied 49 core biopsy specimens of NSCLC for PD-L1, EGFR and HER2-neu expressions using immunohistochemistry. Scoring was based on the intensity and percentage of tumour cells expressing the immunomarkers. PD-L1, EGFR and HER2-neu expression was seen in 20.4%, 32.7% and 14.2% of NSCLC, respectively. The analysis showed no significant difference in PD-L1 expression in relation to any clinicopathological parameters. Low or negative EGFR expression was significantly associated with positive lymph node status (P=0.04). HER2-neu expression showed a significant difference in relation to tumour histology (adenocarcinoma; P=0.01). Also, there was no difference noted with PD-L1 expression in relation to EGFR and HER2-neu expression. As our study has a small number of cases, the validation of the predictive and prognostic value of these markers in lung cancer patients requires further studies.