Prognostic Significance of the Albumin-to-globulin Ratio for Advanced Urothelial Carcinoma Treated with Pembrolizumab: A Multicenter Retrospective Study

Although the albumin-to-globulin ratio (AGR) is a promising biomarker, no study has investigated its prognostic significance for advanced urothelial carcinoma (UC). This study conformed to the REporting recommendations for tumor MARKer prognostic studies (REMARK) criteria. We retrospectively reviewed 176 patients with advanced UC treated with pembrolizumab between 2018 and 2020. We evaluated the associations between pretreatment clinicopathological variables, including the AGR and performance status (PS), with progression-free survival, cancer-specific survival, and overall survival. The Cox proportional hazards model was used for univariate and multivariable analyses. The AGR was dichotomized as < 0.95 and ≥ 0.95 based on receiver operating characteristic curve analysis. After excluding 26 cases with missing data from the total of 176 cases, 109 (73%) patients experienced disease progression, 75 (50%) died from UC, and 6 (4%) died of other causes (median survival = 12 months). Multivariate analyses identified PS ≥ 2 and pretreatment AGR < 0.95 as independent poor prognostic factors for all endpoints. Furthermore, a prognostic risk model incorporating these two variables achieved a relatively high concordance index for all endpoints. This is the first report to evaluate the significance of AGR in advanced UC. Pretreatment AGR < 0.95 may serve as a prognostic marker for advanced UC treated with pembrolizumab.