Correlation between the Expression of PD-L1 and Clinicopathological Parameters in Triple Negative Breast Cancer Patients.

Objective: Triple-negative breast cancer (TNBC) is a heterogenous group of tumors with no estrogen receptor (ER), progesterone receptor (PR) and Cerb-B2/HER2 expression. Programmed death ligand-1 (PD-L1) is a transmembrane protein located on both non-tumor and tumor cells and it has been shown to be associated with the escape of tumor cells from the immune system. PD-L1-targeted therapy alone or in combination is now an alternative strategy in several aggressive tumor types.