Background: Serum bilirubin level, which may reflect the host defense against increased oxidative stress, is inversely associated with the risk of cancer development. In liver transplantation, the intrinsic bilirubin metabolism of donor liver is subsequently translated into recipient. Thus, we hypothesized that liver transplantation conducted with living donors with higher serum bilirubin reduces hepatocellular carcinoma (HCC) recurrence.
Methods: Two hundred fifty recipients who underwent liver transplantation for treating HCC within the Milan criteria were included in the study. The association between donor preoperative total bilirubin concentration and the risk of HCC recurrence was analyzed using the Fine and Gray regression model with posttransplant death as a competing risk event with adjustment for tumor biology including α-fetoprotein, histological differentiation, and microvascular invasion.
Results: All donors were confirmed to have no underlying hepatobiliary diseases or hematological disorders. Donor preoperative total bilirubin concentration was 0.7 mg/dL in median and ranged from 0.2 to 2.7 mg/dL. Thirty-five (14.0%) recipients developed HCC recurrence. Multivariable analysis demonstrated that donor preoperative total bilirubin concentration was inversely associated with the recurrence risk (hazard ratio, 0.22; 95% confidence interval, 0.07-0.72; P = 0.013). The highest (≥1.0 mg/dL) versus lowest (≤0.6 mg/dL) tertile of donor preoperative total bilirubin showed a significant reduction of the recurrence risk (hazard ratio, 0.28; 95% confidence interval, 0.11-0.70; P = 0.006).
Conclusions: Hepatocellular carcinoma recurrence risk decreases in relation to the increase in total serum bilirubin level of healthy living donors without underlying hepatobiliary or hematological disorders. Further validation of bilirubin as a potent anticancer substance against HCC is warranted.