Change in the Neutrophil-to-Eosinophil Ratio After Avelumab Maintenance for Advanced Urothelial Carcinoma: The UROKYU Study

Background/Aim: The association between clinical outcomes and posttreatment changes in the neutrophil-to-lymphocyte ratio (NLR) and neutrophil-to-eosinophil ratio (NER) in patients receiving avelumab maintenance therapy for advanced urothelial carcinoma (UC) is unclear. Patients and Methods: We retrospectively analyzed data from advanced UC patients who received avelumab and had not progressed with first-line platinum-based chemotherapy. The association between the changes in NLR and NER from pretreatment to week 6 of avelumab treatment and therapeutic efficacy was evaluated. Results: Thirty-two patients were enrolled in this study (male, n=25; female, n=7; median age, 71 years). At six weeks, 19 patients (59.4%) had a decreased NLR and 18 patients (56.3%) had a decreased NER. When the change in NER from pretreatment to six weeks was compared, there was a significant decrease in responders (without progressive disease) (p=0.008); however, there was no significant decrease in non-responders (progressive disease) (p=0.855). The NLR showed no significant change in either group (p=0.099, 0.358). When patients were compared according to the change in the NLR at six weeks, progression-free survival (PFS) and overall survival (OS) did not differ between the decreased NLR and increased NLR groups (p=0.116, 0.256). When patients were compared according to the change in the NER, the decreased and increased groups showed significant differences in PFS and OS (p<0.001, 0.030). Conclusion: In the present real-world study, the responders showed a significantly decreased NER at six weeks. This was associated with improved PFS and OS in patients with advanced UC.