B7-H3 expression in upper tract urothelial carcinoma associates with adverse clinicopathological features and poor survival

•B7-H3 positivity associates with adverse upper tract urothelial carcinoma features.•B7-H3 positivity associates with tumor grade, tumor stage and lymph node metastasis.•B7-H3 and B7-H3/PD-L1 positivity associates with poor prognosis.•B7-H3 and B7-H3/PD-L1 positivity may serve as novel prognostic biomarkers. B7-H3, a member of the B7 superfamily, is an immune checkpoint molecule. An association between B7-H3 expression and poor survival has been reported in many types of cancer. However, its prognostic value in patients with upper tract urothelial carcinoma (UTUC) has not yet been reported. The aim of this study was to examine the clinical significance of tumor B7-H3 expression in UTUC. B7-H3 positivity was observed in 36 of 271 cases (13 %) by immunohistochemistry and was significantly associated with several adverse clinicopathological features such as tumor grade, tumor stage, and lymph node metastasis. In addition, B7-H3 positivity was significantly associated with shorter metastasis-free survival and cancer-specific survival. We also found that B7-H3/programmed cell death ligand-1 (PD-L1) co-positivity was significantly associated with worse prognosis. These results suggest the utility of B7-H3 positivity and B7-H3/PD-L1 co-positivity as novel prognostic biomarkers in UTUC, and the potential usefulness of B7-H3 targeted therapy for patients with UTUC, the effect of which may be enhanced by combination with programmed cell death-1 /PD-L1 blockade.