Background: Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) have been explored as biomarkers for response to IO. We investigated the association between these biomarkers and clinical outcomes in urothelial cancer pts treated with IO. Methods: We conducted a retrospective review of 67 urothelial cancer pts treated with PD-1 or PD-L1 inhibitors at Winship Cancer Institute from 2015-2018. Overall survival (OS) and progression free survival (PFS) were measured from first dose of IO to date of death or hospice referral and clinical or radiographic progression, respectively. MLR, NLR, and PLR were collected at C1 and C3. The nonlinear relationship between log-transformed biomarkers and OS or PFS was examined by martingale residual plot and optimal cutoff (OC) values were determined. Multivariable analysis (MVA) used Cox proportional hazard model. Results: OC for C1 and C3 NLR, MLR, and PLR were 2.06 and 1.42, -0.331 and -0.153, and 5.7 and 5.6, respectively. Pts with C1 NLR and PLR above OC had worse OS and shorter PFS (all p<0.05) (Table). High C3 MLR portended shorter OS and PFS. NLR, MLR and PLR were highly correlated (Pearson correlation coefficients ≥ 0.67, p<0.0001). Conclusions: High NLR, MLR, and PLR at C1 and at C3 are associated with worse clinical outcomes in this cohort. These values warrant a larger study for validation. MVA† of MLR, NLR, and PLR at C1 and at C3 with OS and PFS.

†The multivariable model controlled for race, age, performance status, and # of metastatic sites *statistically significant