Neutrophil lymphocyte ratio (NLR) as a clinical biomarker predictive of outcomes with immune checkpoint inhibitor therapy in genitourinary cancers.

Abstract

453 Background: Immune checkpoint inhibitors (ICI) have been approved in genitourinary cancers (GU) such as renal cell carcinoma (RCC) and urothelial carcinoma (UC). There is an unmet need to determine factors predictive of response, to guide therapeutic selection in these cancers. We evaluated NLR as a predictor of response, progression free survival (PFS), and overall survival (OS) in patients treated with ICI. Other known prognostic clinical factors assessed were age, race, and smoking status and for RCC the prognostic score per MSKCC (Memorial Sloan Kettering) and Heng criteria. Methods: Regulatory approval was obtained. A retrospective chart review of RCC and URC patients at Karmanos Cancer Institute, treated with ICI based therapy was conducted. Data was collected on demographics, smoking status, prognostic scoring, NLR pretherapy, and post 4 doses of ICI. Correlation with clinical PFS and OS was conducted by univariable and multivariable analyses. Log-rank test was used to compare PFS and OS. Results: 57 pts were evaluated with median age 62 yrs (range, 24-85). 11 (19%) were African American (AA) and 31 (54%) were smokers. Pretherapy NLR<4 and ≥4 was seen in 38 (67%) and 19 (33%) pts respectively. 13 (31%) RCC pts were treated with > 1 VEGF therapy and 24(57%) pt were treated for > 6 mths and 14/15 UC pts were pretreated. RCC pts treated with > 6 mths and > 12 mths of VEGF therapy had a shorter PFS (HR =2.31, p= 0.028; HR = 2.075, p= 0.051 respectively). AA had shorter PFS and OS with ICI in RCC but not in UC (HR=3.72, p=0.001; HR= 40.8; p=0.001; HR=0.49, p=0.5; HR=0.85, p=0.88, respectively). Conclusions: Pretherapy NLR ≥4 was a statistically significant predictor of shorter PFS and OS with ICI therapy in RCC. NLR is an easily applicable clinical predictive factor that can help guide therapy, after validation of these findings in a larger population dataset. [Table: see text]