Outcomes following liver transplantation for metastatic neuroendocrine tumors

Metastatic disease is generally considered as an absolute contraindication for liver transplantation. However, due to relatively low aggressiveness and slow progression rates, liver metastases from neuroendocrine tumors (NETs) form an exception to this rule. Given the scarcity of available data, the purpose of this study was to evaluate long-term outcomes following liver transplantation for NET metastases.

There were 12 primary liver transplantations in patients with NET metastases out of 1334 liver transplantations performed in the Department of General, Transplant and Liver Surgery (Medical University of Warsaw) in the period between December 1989 and October 2013. Overall survival (OS) and disease-free survival (DFS) were set as primary and secondary outcome measures, respectively.

Median follow-up was 7.9 years. For all patients, OS rate was 78.6% at 10 years and DFS rate was 15.5% at 9 years. Intraoperative transfusions of packed red blood cells (P = .021), Ki-67 proliferative index more than 2% (P = .048), and grade 2 tumors (P = .037) were identified as factors significantly associated with worse DFS. Notably, loss of E-cadherin expression (P = .444), mitotic rate (P = .771), extent of liver involvement (P = .548), primary tumor site (P = .983), and recipient age (P = .425) were not significantly associated with DFS.

Excellent long-term OS rates support liver transplantation for unresectable NET metastases despite almost universal post-transplantation tumor recurrence. Selection of patients with G1 tumors with Ki-67 index not exceeding 2% and reducing the requirement for intraoperative blood transfusions might improve DFS rates.