Prognostic significance of pre-treatment albumin-bilirubin grade in metastatic urothelial carcinoma receiving pembrolizumab

Abstract

Background: Pre-treatment albumin-bilirubin grade is a useful biomarker for predicting prognosis in patients receiving immune checkpoint inhibitors for advanced malignancies. We evaluated the prognostic impact of pre-treatment albumin-bilirubin grade in patients receiving pembrolizumab for metastatic urothelial carcinoma.

Methods: In this multicenter retrospective study, we calculated pre-treatment albumin-bilirubin scores of 96 patients who received pembrolizumab for metastatic urothelial carcinoma between January 2018 and March 2022. Patients were classified according to albumin-bilirubin grade. Progression-free survival and cancer-specific survival were compared between the groups. To evaluate the prognostic impact of pre-treatment albumin-bilirubin grade, we also performed Cox proportional regression analyses for progression-free survival and cancer-specific survival.

Results: The median pre-treatment albumin bilirubin score was -2.52 (quartile: -2.76 to -2.10), and albumin-bilirubin grade was grade 1 in 37 patients (39%), grade 2a in 30 patients (31%), 2b in 22 patients (23%) and grade 3 in 7 patients (7%). The median progression-free survival and cancer-specific survival were 2 and 7 months, respectively. Progression-free survival and cancer-specific survival were significantly different between the albumin-bilirubin grade groups (P < 0.01 and P < 0.01, respectively) and prognosis became poorer as albumin-bilirubin grade increased. High albumin-bilirubin grade was shown in multivariable Cox proportional analyses to be independently associated with both poor progression-free survival and poor cancer-specific survival.

Conclusions: High pre-treatment albumin-bilirubin grade could be a significant independent predictor of poor prognosis in patients receiving pembrolizumab for advanced urothelial carcinoma.

Keywords: biomarkers; immune checkpoint inhibitors; prognosis; ureteral neoplasms; urinary bladder neoplasms.