Downstaging Strategies Prior to Liver Transplantation

Hepatocellular carcinoma (HCC) is the most common liver cancer. The Milan Criteria have stood the test of time and remained the benchmark for selection of candidates for liver transplant (LT). However, it has been proven that a modest expansion of the MC can achieve favorable outcomes. The term downstaging (DS) refers to the application of locoregional therapy (LRT) to tumors outside accepted transplant criteria, with the aim of reducing tumor burden and selecting appropriate candidates for LT. Important factors to consider when assessing the response to DS are: the morphological response; the biological response, usually assessed by the drop in alfa fetoprotein; the stability of disease over time after LRT. Transarterial chemoembolization represents the most used DS approach. Transarterial radioembolization has shown some benefit in downstaging patients with larger tumors and with portal vein tumor thrombosis, which no longer represents an absolute contraindication to the DS protocol. However, several other LRT have been proposed and it is difficult to determine a specific DS method that is more successful than the others. Overall, program specific practices should dictate patient eligibility for DS and individualized treatment decisions must be taken within multidisciplinary teams involving radiologists, hepatologists, surgeons, pathologists and oncologists.