The expression and clinical significance of PD-L1 in patients with upper tract urothelial carcinoma.

Abstract

444 Background: Primary upper tract urothelial carcinoma (UTUC) is rare. In China UTUCs are more common than in Western populations and account for 20–30% of all TCCs.An antibody that targets programmed death ligand-1 (PD-L1) pathway has been shown to be active towards various types of cancer including bladder urothelial carcinoma. In this study, we investigated the PD-L1 expression and prognostic significance in UTUC. Methods: Formalin-fixed paraffin-embedded tumor samples from 78 patients with upper tract urothelial carcinoma from Peking University Cancer Hospital and Peking Universiy First Hospital were retrieved. PD-L1 expression was evaluated by immunohistochemistry using rabbit monoclonal anti-PD-L1 antibody. PD-L1 positivity on tumor cell membrane was defined as ≥ 1% of tumor cell membrane staining.The clinical data of patients were retrospective collected. The multivariate analysis was used to assess the association of PD-L1 expressionwith tumor staging, pathological N classification, whether firstly diagnosed with metastasis, disease free survival(DFS) and overall survival (OS) in patients. Results: The positive rates of PD-L1 expression were 42.3% (33/78) for upper tract urothelial carcinoma. Sex,location, pathological tumor staging, pathological N classification, whether firstly diagnosed with metastasis did not correlate with PD-L1 expression. In patients with upper tract UC, PD-L1 expression was not associated with DFS and OS on univariate analyses. Conclusions: To our knowledge, this is first study about PD-L1 expression in UTUC patients. In this study, We found the PD-L1 expression in UTUC was higher than in the bladder urothelial carcinoma. It means anti-PD-L1 treatment may be better for advanced UTUC. There was no correlation between PD-L1 expression and outcome.