Baseline neutrophil-to-eosinophil ratio (NER) and its association with clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors (CPI).

Abstract

e16569 Background: Inflammatory markers have been studied as prognostic markers in patients with mRCC treated with CPIs. Recently, eosinophilia has been found to be associated with improved survival of patients with melanoma treated with CPIs. We reported baseline NER in patients with mRCC treated with CPIs and its association with clinical outcomes. Methods: We conducted a retrospective analysis of patients with mRCC treated with CPIs at Winship Cancer Institute from 2015-2018. Clinical outcomes were measured as overall survival (OS), progression-free survival (PFS), and clinical benefit (CB). OS and PFS were calculated from CPI-initiation to date of death and radiographic or clinical progression, respectively. Patients with baseline NER were categorized into high or low; high defined as NER > 49.2 and low defined as NER < 49.2. Univariate (UVA) and multivariate (MVA) analyses were carried out for OS and PFS using Cox proportional hazard model. Results: A total of 184 patients were studied with a median follow up of 25.4 months. Median age was 63 years old with 72% male and 20% black. About 25% were in high NER group. The high NER patients had significantly shorter OS in both UVA (HR: 0.58, p-value=0.017) and MVA (HR: 0.62, p-value=0.046) (Table). There was no significant difference between groups for PFS. Clinical benefit was seen in 47.3% of patients with low baseline NER and 40% with high NER. Conclusions: High baseline NER was associated with worse OS in patients with mRCC treated with CPIs. Larger, prospective studies are warranted to validate this hypothesis generating data.[Table: see text]