Predicting post-transarterial chemoembolization outcomes: A comparison of direct and total bilirubin serums levels

Abstract

Purpose: To retrospectively review the ability of direct bilirubin serum level to predict mortality and complications in patients undergoing transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) and compare it to the predictive value of the currently utilized total bilirubin serum level.

Materials and methods: A total of 219 patients who underwent TACE for 353 hepatocelluar carcinomas (HCC) at a single institution were included. There were 165 men and 54 women, with a mean age of 61.4±7.6 (SD) [range: 27-86 years]. The patients' electronic medical records were evaluated and they were divided into cohorts based on total bilirubin (<2, 2-3, and >3mg/dL) as well as direct bilirubin (<1 and 1-2mg/dL).

Results: Direct bilirubin serum level was significantly greater in the cohort of patients who did not survive as compared to those who survived 6 months ([0.58±0.46 (SD) mg/dL; range: <0.1-1.8mg/dL] vs. [0.40±0.31 (SD) mg/dL; range: <0.1-1.6mg/dL], respectively) (P=0.04) and 12 months ([0.49±0.38 (SD) mg/dL; range: <0.1-1.8mg/dL] vs. [0.38±0.32 (SD) mg/dL; range: <0.1-1.6mg/dL], respectively) (P=0.03). While total bilirubin serum level was not significantly different in those who did not and did survive 6 months ([1.54±0.99 (SD) mg/dL; range: 0.3-3.9mg/dL] vs. [1.27±0.70 (SD) mg/dL; range: 0.3-3.75mg/dL], respectively) (P=0.16), it was significantly different when evaluating 12 months survival ([1.46±0.87 (SD)mg/dL; range: 0.3-3.9mg/dL] vs. [1.22±0.65 (SD) mg/dL; range: 0.3-3.9mg/dL]) (P=0.03). Akaike information criterion (AIC) analysis revealed that direct bilirubin level more accurately predicted overall survival (AIC=941.19 vs. 1000.51) and complications (AIC=352.22 vs. 357.42) than total bilirubin serum levels.

Conclusion: Direct bilirubin serum level appears to outperform total bilirubin concentration for predicting complications and overall survival in patients undergoing TACE. Patients with relatively maintained direct bilirubin levels should be considered for TACE, particularly in the setting of bridging to transplant.

Keywords: Bilirubin; Chemoembolization; Cohort studies; Ethiodized oil; Hepatocellular carcinoma.