Real-world programmed death-ligand 1 prevalence rates in non-small cell lung cancer : correlation with clinicopathological features and tumour mutation status

Aims: The detection of programmed death-ligand 1 (PD-L1) protein expression on tumour cells by immunohistochemistry (IHC) is a predictor of response to immune checkpoint inhibitors. New immunotherapeutic options are changing the treatment paradigm for patients with advanced non-small cell lung cancer (NSCLC). The aim of this retrospective study was to investigate real-world prevalence of PD-L1 expression in NSCLC and any correlations with clinicopathological features. Methods: We reviewed 425 NSCLC cases at a Sydney metropolitan hospital that had PD-L1 IHC (SP263 clone) expression estimated as part of routine diagnostic assessment during a 30-month period. Results: Overall, 32.2% of cases were negative for PD-L1 expression (