The Association of Clinical Outcomes with Posttreatment Changes in the Relative Eosinophil Counts and Neutrophil-to-Eosinophil Ratio in Patients with Advanced Urothelial Carcinoma Treated with Pembrolizumab

BACKGROUND: To evaluate the association of clinical outcomes with posttreatment changes in the relative eosinophil count (REC) and neutrophil-to-eosinophil ratio (NER) in patients with advanced urothelial cancer (UC) treated with pembrolizumab. MATERIALS AND METHODS: We retrospectively analyzed 105 patients with advanced UC who received pembrolizumab after the failure of platinum-based chemotherapy. The REC and NER before and three weeks after pembrolizumab were recorded. A receiver operating characteristic curve was used to determine the optimal cut-off values for analyzing the risk. RESULTS: There were no significant differences in the overall survival (OS) between the REC ≥4.8% and <4.8% groups and the NER ≥13.7 and <13.7 groups before pembrolizumab (p=0.997 and 0.669, respectively). However, a significant difference in the OS was confirmed between the increased and decreased REC groups and between the decreased and increased NER groups at 3 weeks after pembrolizumab (p<0.001 and 0.002, respectively). Multivariate analyses revealed that an Eastern Cooperative Oncology Group Performance Status ≥2 (P=0.003), albumin <3.7 g/dl (p=0.002), LDH >246 U/L (p=0.011), disease site ≥3 organs (p=0.019), decreased posttreatment REC (3 weeks later) (p=0.002) and increased posttreatment NER (3 weeks later) (p=0.022) were independent prognostic factors for a worse OS. CONCLUSION: An increased REC and decreased NER after pembrolizumab may be significant early predictive markers of improved clinical outcomes in patients with advanced UC receiving pembrolizumab.