Combined liver-intestinal and multivisceral transplantation for neuroendocrine tumors extending beyond the liver: A systematic literature review

Background: Neuroendocrine tumors (NET) have an increasing incidence and are characterized by an invasive and metastatic presentation, rendering a curative resection not always feasible. For some patients the only life-saving option would be a multivisceral transplantation (MvTx). This systematic review aims to summarize the reported experience on combined liver-intestinal and MvTx for NET according PRISMA-guidelines. Methods: PubMed, EMBASE and Cochrane Controlled Trial Reports were searched until April 7, 2020. Structured data abstraction was performed, and methodological quality assessed. Results: Fourteen single-center and three multicenter retrospective studies reported on 1 combined liver-intestinal and 38 MvTx for NET. Nine previously unreported MvTx were added to the analysis. This review found that: i) overall patient survival of 51.2% is attainable; ii) recurrence of 35% is similar to recurrence after liver transplantation for NET; and iii) NET with diffuse abdominal presentation, normally considered a contraindication, could actually benefit from radical resection and MvTx. Data on tailoring of immunosuppression and (neo-)adjuvant treatment are limited, and further studies are needed to optimize post-transplant management. Conclusions: Although results are encouraging, the reported MvTx experience for NET is limited and requires more detailed prospective multicenter studies and appropriate follow-up and reporting.