Clinical Correlations of Programmed Cell Death Ligand 1 Status in Liquid and Standard Biopsies in Breast Cancer

Background Data regarding the prognostic value of programmed cell death ligand 1 (PD-L1) expression on circulating tumor cells (CTCs) are lacking. However, CTCs could represent an alternative approach to serial biopsies, allowing real-time monitoring of cancer phenotype. Methods We evaluated, in a dedicated prospective clinical trial, the clinicopathological correlations and prognostic value of PD-L1(+)-CTCs in 72 patients with metastatic breast...