C-reactive Protein Is a Prognostic Factor for Survival in Metastatic Upper Tract Urothelial Carcinoma Patients Receiving Pembrolizumab.

Background/aim: The number of available treatment options for urothelial carcinoma has increased recently. Upper tract urothelial carcinoma (UTUC) is relatively rare compared with bladder cancer. There are few reports on the efficacy of immune checkpoint inhibitors (ICIs) for metastatic UTUC, and ICIs may occasionally show less efficacy and cause severe side effects. Therefore, it is important to predict the treatment response and change the treatment strategy as appropriate. We investigated the prognostic factors for treatment response in patients with metastatic UTUC treated with pembrolizumab at our hospital.

Patients and methods: Patients who received pembrolizumab for UTUC between January 2018 and June 2023 were analyzed. Patients who presented with bladder cancer complications at initial diagnosis were excluded. The primary endpoints assessed were overall survival (OS) and progression-free survival (PFS). Statistical analyses were conducted using laboratory values obtained before and after pembrolizumab administration. The relationship between cancer and inflammation is important. Therefore, we analyzed this relationship using prognostic factors for urothelial carcinoma as previously reported. Specifically, pretreatment C-reactive protein (CRP) level, neutrophil-to-lymphocyte ratio (NLR), and NLR/albumin values were examined.

Results: Forty-seven patients were analyzed. The median PFS was 66 days (24-107 days), and the median OS was 164 days (13-314 days). A CRP level <1 before the first cycle was a useful factor in the multivariate analysis for both OS and PFS [OS: p=0.004, hazard ratio (HR)=3.244, 95% confidence interval (CI)=1.464-7.104; PFS: p=0.003, HR=2.998, 95%CI=1.444-6.225].

Conclusion: CRP level is a prognostic factor for pembrolizumab treatment response in patients with UTUC.