Impact of Baseline Cholinesterase in Patients with Primary Liver Tumors Undergoing Radioembolization: Impact on Outcome

The purpose of our study was to determine cutoff values for baseline cholinesterase (CHE) and bilirubin levels prognostic for outcome after radioembolization (RE) in patients with primary liver tumors. In this retrospective single-center study, a threshold for baseline levels of CHE and bilirubin was determined based on overall survival (OS) of patients with refractory primary liver tumors who underwent RE. Between-group differences based on the dichotomized cohort were assessed with the log-rank test. We analyzed N = 92 patients (median age 66.6 years (60.6–73.6 interquartile range), 79% male) with primary liver tumors (57 with hepatocellular carcinoma and 35 with intrahepatic cholangiocarcinoma) who were treated with RE. The median baseline level for bilirubin was 0.7 mg/dl (0.5–1.1 IQR) and for CHE 5.10 kU/l (3.64–6.56), respectively. Median OS in all patients was 429 days (307–550). Cutoff values of baseline bilirubin at 1.6 mg/dl and for CHE at 5 kU/l effectively allowed to differentiate survival groups. In patients with baseline bilirubin ≤ 1.6 mg/dl, OS was significantly higher than in those with bilirubin (> 1.6 mg/dl, P < 0.001). Patients with a baseline CHE of > 5 kU/l showed a significantly longer OS than those with CHE ≤ 5 kU/l, P < 0.001). We suggest that baseline CHE and bilirubin levels have prognostic impact on survival in patients with primary liver tumors after RE. Cutoff values of baseline liver parameters as determined in our study (bilirubin 1.6 mg/dl and CHE 5 kU/l) may help to better select patients eligible for RE.