A Translational Study Investigating PD-L1 Expression After Radiotherapy for Non-small Cell Lung Cancer

Participants with Non-Small Cell Lung Cancer (NSCLC), Performance Status (PS) 0-2, not suitable for concurrent Chemo-Radiotherapy (CTRT), will be treated with standard radiotherapy (radical or palliative). Archival tumour biopsies will be analysed for baseline Programmed Death Ligand 1 (PD-L1) expression. Some participants will have a biopsy before radiotherapy if the archive biopsy is not suitable. Participants will be required to undergo an additional mandatory biopsy of the irradiated site during the second week of radiotherapy.