Programmed Death-ligand 1 Expression in Upper Tract Urothelial Carcinoma

Area of Science:

• Oncology
• Immunology

Background:

• Upper tract urothelial carcinoma (UTUC) represents a small but aggressive subset of urothelial carcinoma.
• Advanced UTUC often presents with poor clinical outcomes and limited treatment options.

Purpose of the Study:

• To investigate the expression of programmed death-ligand 1 (PD-L1) in upper tract urothelial carcinoma (UTUC).
• To determine the association between PD-L1 expression and clinicopathologic features in UTUC.
• To assess the impact of PD-L1 expression on cancer-specific survival in UTUC patients.

Main Methods:

• Retrospective analysis of 149 UTUC cases diagnosed between 1997 and 2016.
• Immunohistochemistry (IHC) using anti-PD-L1 clone 5H1 to evaluate PD-L1 expression on tumor sections.
• Statistical analysis including Fisher's exact test and Cox proportional hazard model to assess associations.

Main Results:

• PD-L1 expression was detected in 32.7% of invasive UTUC and 23.5% of all UTUC cases.
• Positive PD-L1 expression was significantly associated with high histologic grade, advanced pathologic stage, and angiolymphatic invasion.
• No significant association was found between PD-L1 expression (using a 5% cut-off) and cancer-specific survival.

Conclusions:

• Approximately one-third of primary invasive UTUC cases exhibit PD-L1 expression.
• The association of PD-L1 positivity with high-risk clinicopathologic features supports further research into PD-L1-targeted immunotherapeutics for UTUC.
• PD-L1 expression warrants further investigation as a potential therapeutic target in UTUC.