Programmed death ligand-1 (PD-L1) clone 22C3 expression in resected colorectal cancer as companion diagnostics for immune checkpoint inhibitor therapy: A comparison study and inter-rater agreement evaluation across proposed cut-offs and predictive (TPS, CPS and IC) scores

Agreement for PD-L1 was good to excellent for raw scores. Agreement variation across several criteria and cut-offs suggests the need for more robust criteria for PD-L1 as a companion diagnostic marker.