Cytology versus histology for programmed death-ligand 1 expression evaluation in the landscape of non-small cell lung cancer patients selection for immunotherapy

Programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) represent key targets for specific monoclonal antibody inhibitors, such as pembrolizumab, nivolumab and atezolizumab, currently used in clinical practice for the management of metastatic non-small cell lung cancer (NSCLC) patients (1).