CD274 and neoplasm: In the multivariate analysis, a positive correlation was revealed between the expression of Programmed Death-Ligand 1 (PD-L1) on primary tumor cells (TCs) and survival (HR: 5.43; 95% CI: 1.89-15.61; <i>p</i> = 0.0017).<h4>Conclusions</h4>Primary and metastatic tumors differ regarding their tumor microenvironment.