PD-1/PD-L1 pathway: Current research in breast cancer.

Introduction: Immunotherapy has shown encouraging outcomes in breast cancer (BC) treatment in recent years. The programmed cell death ligand 1 (PD-L1) transmembrane protein is suggested to function as a co-inhibitory factor in the immune response, where it collaborates with programmed cell death protein 1 (PD-1) to stimulate apoptosis, suppress cytokine release from PD-1 positive cells, and limit the growth of PD-1 positive cells. Furthermore, in many malignancies, PD-L1 reduces the immune system's response to neoplastic cells.

The expression of programmed death-ligand 1 and its association with histopathological grade, stage of disease, and occurrence of metastasis in breast cancer.

Introduction: Programmed death ligand 1 (PD-L1) plays a role in tumor escape and progression by inactivating T lymphocytes. The aim of the study reported here was to determine the relationship between the expression of PD-L1 and histopathological grade, stage of disease, and the occurrence of metastasis in breast cancer.

Methods: The observational cross-sectional study involved analyzing the expression of PD-L1 by immunohistochemistry.