Introduction

To investigate the prognostic value of PD-1 and PD-L1 expression in patients with high-grade upper tract urothelial carcinoma (UTUC).

Methods

Tissue microarrays were created using 448 patients from the International UTUC collaboration who underwent extirpative surgery for high-grade UTUC and stained for PD-1 (antibody (AB): NAT105, diluted 1:250 from Ventana) and PD-L1 (AB: E1L3N&[copy] prediluted from Cell Signaling). PD-1 and PD-L1 expression was assessed in a semi-quantitative fashion and any percentage of staining of the tumor cells (PD-L1) and tumor-infiltrating lymphocytes (PD-1) was considered positive. Univariate (UVA) and multivariate analyses (MVA) were performed to assess independent prognosticators of oncological outcomes. No funding was received.

Results

Median age of the cohort was 69.2 years and 56.5% of patients were male. PD-L1 and PD-1 were positive in 24.1% and 37.5% of patients. PD-L1 positivity was associated with favorable pathological stage, where as PD-1 positivity was significantly associated with pelvicalyceal location, lymph node metastases, non-organ confined disease, presence of lymphovascular invasion, sessile architecture, necrosis, concomitant CIS, and history of non-muscle invasive bladder cancer. PD-L1 positivity was not significantly associated with survival outcomes. In Cox regression UVA, PD-1 positivity was associated with worse recurrence-free survival (RFS) (HR 1.5 (95%CI 1.08-2.14, p=0.016)), cancer-specific survival (CSS) (HR 1.5 (95%CI 1.07-2.19, p=0.021)), and overall survival (OS) (HR 1.5 (95%CI 1.10-1.97, p=0.009)) (see figure for KM curves). However in MVA, PD-1 positivity was not found to be an independent predictor of RFS, CSS or OS.

Conclusions

PD-1 positivity of tumor-infiltrating lymphocytes was associated with adverse pathological criteria and was a significant prognosticator for RFS, CSS and OS on UVA in patients treated with extirpative surgery for high-grade UTUC in a large, multi-institutional cohort. In MVA, the independent prognostic value of PD-1 was not confirmed. PD-L1 positivity was associated with lower tumor stage, but not with other pathological characteristics or survival outcomes.

Funding

none