Evaluation of the Expression of Programmed Death-Ligand 1 and Its Role in Differentiating Low-Grade and High-Grade Urothelial Carcinoma.

Background: Urothelial carcinoma (UC) is a common malignancy, predominantly affecting males. Many tumor cells use the interaction between programmed death-ligand 1 (PD-L1) and programmed death receptor (PD-1) to inactivate T-cells in the microenvironment and evade host immune response. Our study aims to evaluate the expression of PD-L1 in UC and correlate its expression with histomorphological parameters.