Clinical validity of Metroticket calculator in transplant patients undergoing prior chemoembolization for hepatocellular carcinoma

Abstract

Aim-To test the predictive performance of the Metroticket calculator for survival after liver transplantation (LT) of patients with hepatocellular carcinoma (HCC) undergoing prior transarterial chemoembolization (TACE). Methods-A total of 142 patients treated with TACE and subsequent LT who had arterial enhancing HCC(s) were entered into this analysis. Tumor parameters measured by the enhancement radiological method pre-LT or by pathology post-LT were incorporated into the Metroticket analysis. The calculator was validated in terms of calibration and discrimination capacity. Results-Mean 3- and 5-year survival rates predicted in the radiological model for all 142 patients were 76.4 and 70.1 %, respectively, lying comfortably within the 95 % confidence interval (CI) of the observed survival rate estimates (72.8–86.2 and 68.6–83.2 %, respectively). In the pathological model incorporating microvascular invasion, the mean anticipated survival rate at 5 years of 120 patients with viable nodules on explants was 69.5 %, also lying inside the 95 % CI of the actuarial rates (67.9–83.5 %). The c-indices as measures of discriminatory power were 0.61 and 0.62, respectively, for the 3- and 5-year predictions in the radiological model, and 0.72 for the 5-year prediction in the pathological model. The corresponding findings were similar for subgroups with hepatitis B virus infection and undergoing living-donor LT. Conclusions-The Metroticket calculation based on explant data accurately predicts post-LT survival of HCC patients with prior TACE. Imaging estimate-based predictions before LT appear to provide poorer discrimination than calibration.