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

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.