Role of liver transplantation in the treatment of metastases from neuroendocrine primaries: Patient selection and prediction of outcome

Abstract

Aims: Neuroendocrine metastatic disease is the only secondary malignancy for which orthotopic liver transplantation is considered a viable treatment option. However, lack of agreed-upon criteria for patient selection and perioperative management precludes its widespread use. Methods: Review of published literature. Results: OLT is considered as a treatment option for patients with metastases from a neuroendocrine primary that are extensive, unresectable, or cause symptoms not otherwise controlled. It can also be an option for treatment of disease with unknown primary, as more and more of these cases are now recognised as primary hepatic neuroendocrine tumors. It takes place 6 months after resection of the primary focus in the abscence of recurrence or extrahepatic disease. Hepatomegaly and tumor bulk occupying > 50% of the liver, major simultaneous extrahepatic operation for removal of primary disease, poor tumor differentiation, Ki-67 and E-cadherin overexpression, age >45yrs and inability to perform a R0 resection are the most important factors that herald poor prognosis. In patients with well-differentiated primaries and 0 or 1 adverse factor, 5-yr survival rate has reached 60%–80% and the operation is considered curative in some cases. Disease-free survival can also extend beyond 5yrs, despite immunosuppression. It is suggested that pre-op treatment such as transarterial chemoembolization can minimize tumor load and improve post-op outcomes. OLT is still used as the last available treatment method, with a median time of 34 months from diagnosis to transplantation. The lack of commonly established criteria for patient selection makes benefit assessment difficult, as most series are small and include retrospectively collected data. Conclusions: OLT is emerging as a potent therapeutic modality for patients with neuroendocrine metastases. Establishment of widely accepted patient selection criteria and close follow-up will aid in its establishment as a potentially life-saving intervention.