The poor antitumor effect of pembrolizumab in advanced upper urothelial carcinoma with renal parenchymal invasion

Objectives We investigated poor prognosticators in advanced or unresectable urothelial carcinoma, focusing on renal parenchymal invasion (RPI). Methods This study included 48 bladder cancer (BC) and 67 upper tract urothelial carcinoma (UTUC) patients treated with pembrolizumab from December 2017 to September 2022 at Kobe University Hospital. Medical records were retrospectively reviewed for clinical characteristics, objective response rate (ORR), progression‐free survival (PFS), and overall survival (OS). Multivariate analyses were performed using the Cox proportional hazard regression model to identify parameters associated with either PFS or OS. Results Of 67 UTUC patients, 23 had RPI and 41 patients did not, while 3 cases could not be evaluated. Patients with RPI were predominantly elderly and had liver metastases. ORR for patients with RPI was 8.7%, while it was 19.5% for those without RPI. PFS was significantly shorter for patients with RPI compared with those without RPI. Patients with RPI had significantly shorter OS than those without RPI. On multivariate analysis, performance status (PS) ≥ 2, neutrophil‐lymphocyte ratio (NLR) ≥ 3, C‐reactive protein ≥0.3 mg/dL and RPI were independent prognostic factors for PFS. PS ≥ 2, NLR ≥ 3, visceral metastasis and RPI were independent prognostic factors for OS. UTUC patient OS was significantly shorter than BC patient OS, while no significant difference in PFS or OS was observed between BC patients and UTUC patients without RPI. Conclusions RPI was a poor prognostic factor in advanced urothelial carcinoma treated with pembrolizumab, possibly resulting in a poorer prognosis for UTUC compared with BC.