MEDICINE, vol.98, no.33, 2019 (SCI-Expanded)
Conventional therapy modalities for advanced breast cancer are problematic, whereas checkpoint blockade immunotherapy has been considered as a promising approach. This study aims to determine programmed death-ligand 1 (PD-L1) expression and methylation status of PD-L1 promoter in primary tumor tissue and metastatic foci of patients with stage IV breast cancer.