Association between serum albumin-creatinine ratio and survival in patients treated with immune checkpoint inhibitors

Abstract

Abstract Background The objective of this study is to assess the correlation between survival outcomes and sACR in patients who are treated with immune checkpoint inhibitors (ICIs). Methods This study was conducted on individuals who were administered ICI at least 3 doses from 2018 to 2023. Serum-albumin creatinine ratio (sACR) was measured using serum albumin and creatinine values before the immunotherapy. Based on the median level, the patients were divided into two groups: sACR-High and sACR-Low. The relationship between sACR and progression-free survival (PFS) and overall survival (OS), was estimated using the Kaplan-Meier method along with long-rank testing and Cox proportional hazard models. The relationship between sACR and early progression, late progression, and long-term benefit was estimated using a logistic regression method. Results A total of 434 patients were included. Patients were divided into sACR-low and high subgroups according to the median. In the multivariate analyses, patients with lower sACR had decreased OS (HR:1.42, 95% CI 1.07–1.89 p = 0.014) and PFS (HR:1,36, 95% CI 1.09–1.70, p = 0.007). Also, after adjustment for gender, age, and Eastern Cooperative Oncology Group (ECOG) score; sACR was associated with early progression ( HR: 1.86 95% CI, 1.14–3.01 p = 0.012), late progression (HR: 2.06, 95% CI 1.0-4.24 p = 0.050) and long-term benefit of ICIs (HR: 1.72, 95% CI 1.002–2.93 p = 0.049). Conclusions It was found that sACR, a marker easily obtained through routine biochemistry testing at low cost, could serve as an independent predictor of PFS and OS patients undergoing immunotherapy. Routine lab tests performed for cancer patients may help clinicians identify high-risk patients in whom closer follow-up or protective measures should be considered.