Liver Transplantation in Malignancies: A Comprehensive and Systematic Review on Oncological Outcome

Liver Transplant as a Treatment of Primary and Secondary Liver Neoplasms

Importance

Liver malignancies are an increasing global health concern with a high mortality. We review outcomes following liver transplant for primary and secondary hepatic malignancies.

Observations

Transplant may be a suitable treatment option for primary and secondary hepatic malignancies in well-selected patient populations.

Conclusions and Relevance

Many patients with primary or secondary liver tumors are not eligible for liver resection because of advanced underlying liver disease or high tumor burden, precluding complete tumor clearance. Although liver transplant has been a long-standing treatment modality for patients with hepatocellular carcinoma, recently transplant has been considered for patients with other malignant diagnoses. In particular, while well-established for hepatocellular carcinoma and select patients with perihilar cholangiocarcinoma, transplant has been increasingly used to treat patients with intrahepatic cholangiocarcinoma, as well as metastatic disease from colorectal liver and neuroendocrine primary tumors. Because of the limited availability of grafts and the number of patients on the waiting list, optimal selection criteria must be further defined. The ethics of organ allocation to individuals who may benefit from prolonged survival after transplant yet have a high incidence of recurrence, as well as the role of living donation, need to be further discerned in the setting of transplant oncology.

Liver transplantation in the management of cholangiocarcinoma: Evolution and contemporary advances

Cholangiocarcinoma (CCA) is an aggressive malignancy arising from the biliary epithelium. It may occur at any location along the biliary tree with the perihilar area being the most common. Prognosis is poor with 5-year overall survival at less than 10%, typically due to unresectable disease at presentation. Radical surgical resection with clear margins offers a chance of cure in patients with resectable tumours, but is frequently not possible due to locally advanced disease. On the other hand, orthotopic liver transplantation (LT) allows for a radical and potentially curative resection for these patients, but has been historically controversial due to the limited supply of donor grafts and previously poor outcomes. In patients with perihilar CCA, within specific criteria and following the implementation of a protocol combining neoadjuvant chemoradiation and LT, excellent results have been achieved in the last decades, resulting in its increasing acceptance as an indication for LT and the standard of care in several centres with significant experience. However, in intrahepatic CCA, the role of LT remains controversial and owing to dismal previous results it is not an accepted indication. Nevertheless, more recent studies have demonstrated favourable results with LT in early intrahepatic CCA, indicating that, under defined criteria, its role may increase in the future. This review highlights the history and contemporary advances of LT in CCA, with particular focus on the improving outcomes of LT in intrahepatic and perihilar CCA and future perspectives.

Liver Transplant Oncology: Towards Dynamic Tumor-Biology-Oriented Patient Selection

While liver transplantation was initially considered as a curative treatment modality only for hepatocellular carcinoma, the indication has been increasingly extended to other tumor entities over recent years, most recently to the treatment of non-resectable colorectal liver metastases. Although oncologic outcomes after liver transplantation (LT) are consistently good, organ shortage forces stringent selection of suitable candidates. Dynamic criteria based on tumor biology fulfill the prerequisite of an individual oncological prediction better than traditional morphometric criteria based on tumor burden. The availability of specific (neo-)adjuvant therapies and customized modern immunosuppression may further contribute to favorable post-transplantation outcomes on the one hand and simultaneously open the path to LT as a curative option for advanced stages of tumor patients. Herein, we provide an overview of the oncological LT indications, the selection process, and expected oncological outcome after LT.