Immunohistochemical staining
tumor, tumors
CPS, TUMOR, TUMORS
PD-L1 expression analysis of formalin-fixed paraffin-embedded (FFPE) tumors at baseline was performed using PD-L1 immunohistochemistry 22C3 pharmDx assay (Agilent Technologies) on a Dako Autostainer Link 48 automated platform following an automated staining manual. CPS was defined as the number of PD-L1 positive cells (including tumor cells, macrophages and lymphocytes) divided by the total number of tumor cells, multiplied by 100.