The Impact of Neutrophil-to-Lymphocyte Ratio after Two Courses of Pembrolizumab for Oncological Outcomes in Patients with Metastatic Urothelial Carcinoma.

We focused on the therapeutic effect of pembrolizumab for metastatic urothelial carcinoma (mUC) and evaluated predictive factors for improving clinical outcomes. We conducted a retrospective multicenter cohort study of patients with mUC who received pembrolizumab. The endpoint was to evaluate the association between clinicopathological features and oncological outcomes. A total of 160 patients were enrolled in this study and were divided into two groups: the responder and the non-responder group, according to the best response. They were followed up for a median period of 10 months. The median overall (OS) and progression-free survival (PFS) in this study were 17 and 4 months, respectively. The responder group did not achieve median OS and it was 10 months in the non-responder group (p < 0.001). Similarly, the responder group did not achieve PFS, and it was 2 months in the non-responder group (p < 0.001). Regarding the neutrophil-to-lymphocyte ratio (NLR) after two courses of administration of pembrolizumab, patients with NLR < 3.24 had significantly better oncological outcomes than those with NLR ≥ 3.24. Multivariate analysis showed a significant association between NLR after two courses of pembrolizumab and OS. Therefore, the absolute value of NLR after two courses of pembrolizumab was a significant predictive factor for oncological outcomes.