Association of serum total bilirubin with survival outcomes in patients with cancer cachexia: A prospective, multicenter cohort study

Abstract

ObjectivesCancer cachexia is a systemic paraneoplastic phenomenon involving multiple organs, including the liver. Total bilirubin (TBIL) is an easily obtained blood biomarker that reflects liver homeostasis. The aim of this study was to evaluate the prognostic value of serum TBIL in patients with cancer cachexia. MethodsThis study included 2282 patients from a multicenter research database who were diagnosed with cancer cachexia between June 2012 and December 2019. The hazard ratio (HR) for all-cause mortality was analyzed using Cox proportional hazards regression models. The association of serum TBIL with all-cause mortality was modeled with restricted cubic splines. The optimal cutoff value for TBIL was calculated with maximally selected rank statistics. ResultsOf the participants, there were 1327 (58.2%) men and 955 (41.8%) women. The mean patient age was 60.4 ± 1.5 y. The 12-mo all-cause mortality rate for patients with cancer cachexia was 29.5% (95% confidence interval [CI], 27.6%–31.3%), resulting in a rate of 209.58 events per 1000 patient-years. An inverted L-shaped association between TBIL and all-cause mortality was observed. The cutoff point for TBIL for the prediction of the time to mortality was <21.7 µmol/L. A high TBIL level but not the direct bilirubin or indirect bilirubin level was identified as an independent prognostic factor (HR, 1.60; 95% CI, 1.32–1.93). For patients with digestive system tumors, a high serum TBIL level (≥21.7 µmol/L) was significantly associated with mortality. ConclusionHigh TBIL levels are associated with increased all-cause mortality in patients and might be a promising prognostic indicator in patients with cancer cachexia.