Transplantation for hepatocellular cancer: pushing to the limits?

Milan criteria (MC) represents the cornerstone in the selection of patients with hepatocellular cancer (HCC) waiting for liver transplantation (LT). MC represent the precursor of the scores based on the idea of "utility": in other terms, the scoring systems typically used in the field of LT oncology present the exclusive aim of selecting the cases with the best post-LT outcomes. However, some other scores have been proposed specifically investigating the risk of death or tumour progression during the waiting list. In this case, the selection process is connected with the idea of "priority": patients at higher risk for drop-out (DO) should be selected, prioritising them or, conversely, deciding to de-list them due to the high risk of post-LT futile transplant. Lastly, models based on the concept of "benefit", namely the balancing between priority and utility, have been recently created. The present review aims to examine these three different types of scoring systems, trying to underline their pro and cons in the allocation process of HCC patients.