13 C-Methacetin Breath Test Predicts Survival in Patients With Hepatocellular Carcinoma Undergoing Transarterial Chemoembolization

INTRODUCTION: The 13 C-methacetin breath test ( 13 C-MBT) is a dynamic method for assessing liver function. This proof-of-concept study aimed to investigate the association between 13 C-MBT values and outcomes in patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE). METHODS: A total of 30 patients with HCC were prospectively recruited. Of these, 25 were included in baseline and 20 in longitudinal analysis. 13 C-MBTs were performed before the first and second TACE session. Patients were followed for at least 1 year. RESULTS: At baseline, the median 13 C-MBT value was 261 μg/kg/hr (interquartile range 159-387). 13 C-MBT, albumin-bilirubin, Child-Pugh, and Model for End-Stage Liver Disease scores were associated with overall survival in extended univariable Cox regression ( 13 C-MBT: standardized hazard ratio [sHR] 0.297, 95% confidence interval [CI] 0.111-0.796; albumin-bilirubin score: sHR 4.051, 95% CI 1.813-9.052; Child-Pugh score: sHR 2.616, 95% CI 1.450-4.719; Model for End-Stage Liver Disease score: sHR 2.781, 95% CI 1.356-5.703). Using a cutoff of 140 μg/kg/hr at baseline, 13 C-MBT was associated with prognosis (median overall survival 28.5 months [95% CI 0.0-57.1] vs 3.5 months [95% CI 0.0-8.1], log-rank P < 0.001). Regarding prediction of 90-day mortality after second 13 C-MBT, the relative change in 13 C-MBT values yielded an area under the receiver-operating characteristic curve of 1.000 ( P = 0.007). DISCUSSION: Baseline and longitudinal 13 C-MBT values predict survival of patients with HCC undergoing TACE. The relative change in 13 C-MBT values predicts short-term mortality and may assist in identifying patients who will not benefit from further TACE treatment.