De Ritis Ratio, Neutrophil-to-Lymphocyte Ratio, and Albumin Are Significant Prognostic Factors for Survival Even After Adjusted by the Treatment Duration in Metastatic Kidney and Bladder Cancer Treated With Immune-Checkpoint Inhibitors

Purpose: This study aimed to determine the prognostic roles of several immune-related laboratory parameters in patients with metastatic kidney and bladder cancer treated with immune checkpoint inhibitors (ICIs).Materials and Methods: Overall, 36 patients with either metastatic bladder (N=18) or kidney cancer (N=18) were enrolled retrospectively. Progression-free survival (PFS) and overall survival according to the pretherapeutic serum De Ritis ratio (DRR), neutrophil-to-lymphocyte ratio (NLR), and albumin level after ICI treatment, were analyzed. Treatment duration was adjusted using Contal and O’Quigley’s method to explore the cutoff and maximize the log-rank test statistic. Cox proportional hazards model was used to analyze the laboratory parameters.Results: A total of 9 patients received a combination therapy of multiple ICIs (N=9) and targeted agents (N=7). The median NLR, DRR, and albumin level at baseline were 1.7, 1.2, and 4.2 mg/dL, respectively. In the univariable analysis, combination of immunotherapies, total ICI cycles, baseline DRR, and albumin level were significant for PFS. Sex ratio, total ICI cycles, and baseline NLR and DRR were significant for cancer-specific survival (CSS). DRR and albumin levels, which were measured for up to 10 cycles, were significant in PFS and CSS. NLR was additionally significant in CSS. After adjusting total ICI cycles, DRR was significant in PFS and CSS, albumin level was significant only in PFS, and NLR was significant only in CSS in the multivariable analysis.Conclusions: NLR, DRR, and albumin level are significant factors associated with the survival of patients with metastatic kidney and bladder cancer treated with ICI.