Liver transplantation for neuroendocrine tumors in Europe-results and trends in patient selection: A 213-case European liver transplant registry study. Ann Surg. 2013;257:807-815. [PMID: 23532105 DOI: 10.1097/sla.0b013e31828ee17c]

Liver transplantation for metastatic neuroendocrine tumors

Neuroendocrine tumors are a heterogeneous group of rare epithelial tumors. Most of them are metastatic at the time of initial diagnosis. Liver transplantation (LT) has been proposed in selected patients with diffuse liver involvement. Rationale for LT in this indication is based on the frequently indolent nature of neuroendocrine tumors, the propensity for liver-only metastasis and the high rate of intrahepatic recurrence after resection. However, indications for LT for neuroendocrine liver metastases remain controversial, and patient selection criteria is still a matter of debate. The aim of this review is to summarize data regarding LT for neuroendocrine liver metastases by answering frequently asked questions about this issue.

Liver transplantation for neuroendocrine tumors: review of the literature and future perspectives

Liver transplantation for metastases of neuroendocrine tumors is still a subject of controversial discussion. Over the years, more and more data have been collected to demonstrate that transplantation is feasible and contributes to long-term overall survival. Most data are of retrospective nature and, thus, it is difficult to draw definitive conclusions. Over the years, indications, surgical technique and perioperative care have improved. The most recent data have been collected prospectively and show a very favorable outcome in selected patients. Liver transplantation should be considered in patients with neuroendocrine liver metastases, but the decision needs to be made on an individual basis with particular emphasis on the tumor biology. In the future, we may need to work more with living organ donation and perhaps, especially in Europe, think about challenging the scoring system model of end-stage liver disease for this indication.

Indication for liver transplantation in young patients with small intestinal NETs is rare?

BACKGROUND

A majority of patients with small intestinal neuroendocrine tumors (SI-NETs) present with or develop liver metastases (LM). A number of treatments for LM are used clinically, including liver transplantation (LTx). Indications for LTx are under debate; young age(<65 years), absence of extrahepatic disease, resected primary tumor and limited extent of LM have been suggested as inclusion criteria for LTx with the aim to optimize outcome.

MATERIALS AND METHODS

From our series of 672 patients with SI-NET treated at the University Hospital in Uppsala between 1985 and 2012, we identified 78 patients according to the following criteria: <65 years of age, locoregional surgery (LRS) of the primary tumor and mesenteric metastases successfully performed, LM present but no extrahepatic disease. Baseline was chosen as the first date the following points were met: First visit to our center,LRS performed, LM present. The patients underwent treatment according to the standard clinical protocols at our center, and during this time period we did not perform or refer any SI-NET patients for LTx. Kaplan-Meier survival analyses were performed in three different groups based on hypothetical criteria for LTx.

RESULTS

Five-year overall survival rates for patients <65 years (n = 78) and <55 years (n = 36) of age were 84 ± 8 and 92 ± 9 %, respectively. For patients fulfilling the Milan criteria (n = 33) the 5-year survival was 97 ± 6 %.

CONCLUSIONS

Most young patients (<65 years) with SINET and LM have a favorable survival with standardized multimodality treatment. Indeed, most survival figures reported after LTx of NET do not surpass these figures.

Liver transplantation for metastatic neuroendocrine tumors

The ideal management of NET must be addressed on a case-by-case basis, with consideration given to patient factors, disease burden, and clinical tumor activity. Outcome improvement for LT in the setting of metastatic disease requires better characterization of the biological behavior of NETs and further identification of factors to be included in the selection criteria. Box 3 summarizes the many areas that have been, and are currently, undergoing investigation. LT as an attempt for cure rather than palliation is a justified treatment option for well-selected patients with metastatic neuroendocrine tumors of the pancreas and GI system. Optimization of pretransplantation staging and patient management algorithms, patient selection, and posttransplant management options are areas that need to be better defined. Further investigations for defining reproducible prognostic factors, consistent histopathologic evaluation, and uniform preoperative staging and site-specific data are needed. With the advancement of newer treatment modalities, it is necessary to define the role of LT along with the optimal perioperative management of existing and recurrent disease.

Role of surgery and transplantation in the treatment of hepatic metastases from neuroendocrine tumor

Neuroendocrine tumors (NET) are a heterogeneous group of cancers, with indolent behavior. The most common primary origin is the gastro-intestinal tract but can also appear in the lungs, kidneys, adrenals, ovaries and other organs. In general, NET is usually discovered in the metastatic phase (40%-80%). The liver is the most common organ involved when metastases occur (40%-93%), followed by bone (12%-20%) and lung (8%-10%).A number of different therapeutic options are available for the treatment of hepatic metastases including surgical resection, transplantation, ablation, trans-arterial chemoembolization, chemotherapy and somatostatin analogues. Recently, molecular targeted therapies have been used, usually in combination with other treatment options, to improve outcomes in patients with metastases. This article emphasizes on the role of surgery in the treatment of liver metastases from NET.

A tale of two tumors: treating pancreatic and extrapancreatic neuroendocrine tumors

Despite their perceived rarity, gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rising in incidence and prevalence. The biology, natural history, and therapeutic options for GEP-NETs are heterogeneous: NETs arising in the pancreas can be distinguished from those arising elsewhere in the gastrointestinal tract, and therapy is dichotomized between these two groups. Somatostatin analogues are the mainstay of oncologic management of bowel NETs; everolimus, streptozocin, and sunitinib are approved to treat pancreatic NETs. There are significant differences in molecular genetics between pancreatic and extrapancreatic NETs, and studies are evaluating whether additional NET patients may benefit from targeted agents. We discuss the distinguishing features of these two groups of tumors, as well as the therapeutic implications of the distinction. We also examine the evolving therapeutic landscape and discuss the likelihood that treatment will be developed independently for pancreatic and extrapancreatic gastrointestinal NETs, with novel therapeutics effective for newly identified pathologically or molecularly defined subgroups.

Nordic guidelines 2014 for diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

BACKGROUND

The diagnostic work-up and treatment of patients with neuroendocrine neoplasms (NENs) has undergone major recent advances and new methods are currently introduced into the clinic. An update of the WHO classification has resulted in a new nomenclature dividing NENs into neuroendocrine tumours (NETs) including G1 (Ki67 index ≤ 2%) and G2 (Ki67 index 3-20%) tumours and neuroendocrine carcinomas (NECs) with Ki67 index > 20%, G3. Aim. These Nordic guidelines summarise the Nordic Neuroendocrine Tumour Group's current view on how to diagnose and treat NEN-patients and are meant to be useful in the daily practice for clinicians handling these patients.

Outcomes following liver transplantation for metastatic neuroendocrine tumors

INTRODUCTION

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.

MATERIAL AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Therapeutic strategies for neuroendocrine liver metastases

Patients who have neuroendocrine tumors frequently present with liver metastases. A wide panel of treatment options exists for these patients. Liver resection with curative intent achieves the best long-term results. Highly selected patients may be considered for liver transplantation. Substantial recurrence rates reported after surgical approaches call for neoadjuvant and adjuvant concepts. Liver-directed, locally ablative procedures are recommended for patients with limited, nonresectable tumor burden. Angiographic liver-directed techniques, such as transarterial embolization, transarterial chemoembolization, and selective internal radiotherapy, offer excellent palliation for patients with liver-predominant disease. Peptide receptor radionuclide therapy is a promising palliative procedure for patients with hepatic and/or extrahepatic metastases. The efficacy of these treatment options needs to be evaluated in randomized trials. Somatostatin analogues have demonstrated effectiveness not only for symptomatic relief in patients with secreting tumors but also for the control of proliferation in small intestinal neuroendocrine tumors and most recently also in those originating from the pancreas. Chemotherapy is an option mainly for those with pancreatic neuroendocrine tumors and high-grade tumors irrespective of the origin. Novel drugs targeting specific pathways within the tumor cell have produced improved progression-free survival compared with placebo in patients with pancreatic neuroendocrine tumors. Despite such a diverse armamentarium, there is uncertainty with regard to the optimal treatment regimens. Newly introduced molecular-based markers, along with the conduction of clinical trials comparing the efficacy of treatment modalities, offer a chance to move the treatment of neuroendocrine tumor disease toward personalized patient care. In this report, the authors review the approaches for treatment of neuroendocrine liver metastases, identify shortcomings, and anticipate future perspectives. Furthermore, clinical practice recommendations are provided for currently available treatment options. Although multiple modalities are available for the treatment of neuroendocrine liver metastases, optimal management is unclear. The current knowledge pertaining to these treatment options is analyzed.

GEP-NETS update: a review on surgery of gastro-entero-pancreatic neuroendocrine tumors

The incidence of neuroendocrine tumors (NETs) has increased in the last decades. Surgical treatment encompasses a panel of approaches ranging from conservative procedures to extended surgical resection. Tumor size and localization usually represent the main drivers in the choice of the most appropriate surgical resection. In the presence of small (<2 cm) and asymptomatic nonfunctioning NETs, a conservative treatment is usually recommended. For localized NETs measuring above 2 cm, surgical resection represents the cornerstone in the management of these tumors. As they are relatively biologically indolent, an extended resection is often justified also in the presence of advanced NETs. Surgical options for NET liver metastases range from limited resection up to liver transplantation. Surgical choices for metastatic NETs need to consider the extent of disease, the grade of tumor, and the presence of extra-abdominal disease. Any surgical procedures should always be balanced with the benefit of survival or relieving symptoms and patients' comorbidities.

Surgical management of advanced pancreatic neuroendocrine tumors: short-term and long-term results from an international multi-institutional study

BACKGROUND

The role of extended resections in the management of advanced pancreatic neuroendocrine tumors (PNETs) is not well defined.

METHODS

Between 1995 and 2012, 134 patients with PNET underwent isolated (isoPNET group: 91 patients) or extended pancreatic resection (synchronous liver metastases and/or adjacent organs) (advPNET group: 43 patients).

RESULTS

The associated resections included 27 hepatectomies, 9 vascular resections, 12 colectomies, 10 gastrectomies, 4 nephrectomies, 4 adrenalectomies, and 3 duodenojejunal resections. R0 was achieved in 41 patients (95%) in the advPNET. The rates of T3-T4 (73 vs 16%; p < .0001) and N+ (35 vs 13%; p = .007) were higher in the advPNET group. Mortality (5 vs 2%) and major morbidity (21 vs 19%) rates were similar between the 2 groups. The 5-year overall survival (OS) of the series was 87% in the isoPNET group and 66% in the advPNET group (p = .006). Only patients with both locally advanced disease and liver metastases showed worse survival (p = .0003). The advPNET group developed recurrence earlier [disease-free survival (DFS) at 5 years: 26 vs 81%; p < .001]. In univariate analysis, negative prognostic factors of survival were: poor degree of differentiation (p < .001), liver metastasis (p = .011), NE carcinoma (p < .001), and resection of adjacent organs (p = .013). The multivariate analysis did not highlight any factor that influenced OS. In multivariate analysis independent DFS factors were a poor degree of differentiation (p = .03) and the European Neuroendocrine Tumor Society stage (p = .01).

CONCLUSIONS

An aggressive surgical approach for locally advanced or metastatic tumors is safe and offers long-term survival.

Pancreatic neuroendocrine tumor accompanied with multiple liver metastases

Pancreatic neuroendocrine tumor (P-NET) is rare and slow-growing. Current classifications predict its prognosis and postoperative recurrence. Curative resection is ideal, although often difficult, because over 80% of patients have unresectable multiple liver metastases and extrahepatic metastasis. Aggressive surgery for liver metastases is important to improve survival. Aggressive or cytoreductive surgery for liver metastases is indicated to reduce hormone levels and improve symptoms and prognosis. Liver transplantation was originally conceived as an ideal therapy for unresectable liver metastases. Unfortunately, there is no clear consensus on the role and timing of surgery for primary tumor and liver metastases. Surgeons still face questions in deciding the best surgical scenario in patients with P-NET with unresectable liver metastases.

Small bowel neuroendocrine tumors: the benefits of surgical intervention

Well-differentiated SI NETs are on the rise. Due in part to the indolent nature of these tumors, patients typically have a delay in diagnosis and present with metastatic disease. Surgeries for symptoms of either chronic intermittent small bowel obstruction and/or ischemia or from carcinoid syndrome have proven to provide excellent palliation. Most recently, several series have demonstrated an improved survival in those patients in whom the primary, locoregional disease has been resected. Several newer adjuncts have been developed to aid in the hepatic directed therapies such as ablation therapies, embolization and Y spheres. The ability to cytoreduce 70% or more of the hepatic tumor burden has been shown to not only to provide a biochemical and as such a clinical response, but also appears to prolong survival. All patients with SI NETs should be assessed in a multidisciplinary clinic and the first line of therapy should always be to assess surgical resectabilty.

Management of patients with hepatic metastases from neuroendocrine tumors

Neuroendocrine tumors have a disposition toward metastasis to the liver. A range of treatment modalities for neuroendocrine liver metastases is available in the clinical arena, the indications for which depend on tumor characteristics such as patterns of metastasis, tumor grade, and anatomical origin. The complete surgical resection of liver deposits represents the only option with the intent to cure and is the gold standard approach, whereas cytoreductive resection (debulking) presents another surgical option aiming to ameliorate the symptoms and prolong survival. Liver transplantation is generally an accepted option for highly selected patients. For patients ineligible for radical surgery, liver-directed therapies-transarterial embolization/chemoembolization, selective internal radiotherapy, and local tumor ablation-present alternative strategies. Systemic therapies include peptide receptor radiotherapy, somatostatin analogues, cytotoxic chemotherapeutics, and novel molecularly targeted drugs. However, despite the variety of treatments available, there exists little evidence to guide optimal clinical practice with currently available data predominantly retrospective in nature. In this review, we discuss the diagnostic procedures that influence the trajectory of treatment of patients with neuroendocrine liver metastases before critically appraising the evidence pertaining to these therapeutic strategies.

Liver transplantation for metastatic liver malignancies

PURPOSE OF REVIEW

Liver transplantation is a validated treatment of primary hepatobiliary tumours. Over the last decade, a renewed interest for liver transplantation as a curative treatment of colorectal liver metastasis (CR-LM) and neuro-endocrine metastasis (NET-LM) has developed.

RECENT FINDINGS

The ELTR and UNOS analyses showed that liver transplantation may offer excellent disease-free survival (ranging from 30 to 77%) in case of NET-LM, on the condition that stringent selection criteria are implemented. The interest for liver transplantation in the treatment of CR-LM has been fostered by the Norwegian SECA study. Five-year A 5-year survival rate of 60% could be reached. Despite the high recurrence rate (90%), one-third of patients were disease free following pulmonary surgery for metastases.

SUMMARY

Liver transplantation will take a more prominent place in the therapeutic algorithm of CR-LM and NET-LM. Larger experiences are necessary to improve knowledge about tumour biology and to refine selection criteria. A multimodal approach adding neo and adjuvant medical treatment to the transplant procedure will be key to bring this oncologic transplant project into the clinical arena. The preserved liver function in these patients will allow a more deliberate access to split liver and living donation for these indications.

Current status of the organ replacement approach for malignancies and an overture for organ bioengineering and regenerative medicine

Significant achievements in the organ replacement approach for malignancies over the last 2 decades opened new horizons, and the age of "Transplant Oncology" has dawned. The indications of liver transplantation for malignancies have been carefully expanded by a strict patient selection to assure comparable outcomes with non-malignant diseases. Currently, the Milan criteria, gold standard for hepatocellular carcinoma, are being challenged by high-volume centers worldwide. Neoadjuvant chemoradiation therapy and liver transplantation for unresectable hilar cholangiocarcinoma has been successful in specialized institutions. For other primary and metastatic liver tumors, clinical evidence to establish standardized criteria is lacking. Intestinal and multivisceral transplantation is an option for low-grade neoplasms deemed unresectable by conventional surgery. However, the procedure itself is in the adolescent stage. Solid organ transplantation for malignancies inevitably suffers from "triple distress," i.e., oncological, immunological, and technical. Organ bioengineering and regenerative medicine should serve as the "triple threat" therapy and revolutionize "Transplant Oncology."

Liver transplantation for hepatic tumors: A systematic review

Improvements in the medical and pharmacological management of liver transplantation (LT) recipients have led to a better long-term outcome and extension of the indications for this procedure. Liver tumors are relevant to LT; however, the use of LT to treat malignancies remains a debated issue because the high risk of recurrence. In this review we considered LT for hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), liver metastases (LM) and other rare tumors. We reviewed the literature, focusing on the past 10 years. The highly selected Milan criteria of LT for HCC (single nodule < 5 cm or up to 3 nodules < 3 cm) have been recently extended by a group from the University of S. Francisco (1 lesion < 6.5 cm or up to 3 lesions < 4.5 cm) with satisfying results in terms of recurrence-free survival and the “up-to-seven criteria”. Moreover, using these criteria, other transplant groups have recently developed downstaging protocols, including surgical or loco-regional treatments of HCC, which have increased the post-operative survival of recipients. CCA may be treated by LT in patients who cannot undergo liver resection because of underlying liver disease or for anatomical technical challenges. A well-defined protocol of chemoirradiation and staging laparotomy before LT has been developed by the Mayo Clinic, which has resulted in long term disease-free survival comparable to other indications. LT for LM has also been investigated by multicenter studies. It offers a real benefit for metastases from neuroendocrine tumors that are well differentiated and when a major extrahepatic resection is not required. If LT is an option in these selected cases, liver metastases from colorectal cancer is still a borderline indication because data concerning the disease-free survival are still lacking. Hepatoblastoma and hemangioendothelioma represent rare primary tumors for which LT is often the only possible and effective cure because of the frequent multifocal, intrahepatic nature of the disease. LT is a very promising procedure for both primary and secondary liver malignancies; however, it needs an accurate evaluation of the costs and benefits for each indication to balance the chances of cure with actual organ availability.

Liver transplantation for malignancy: Current treatment strategies and future perspectives

In 1967, Starzl et al performed the first successful liver transplantation for a patient diagnosed with hepatoblastoma. In the following, liver transplantation was considered ideal for complete tumor resection and potential cure from primary hepatic malignancies. Several reports of liver transplantation for primary and metastatic liver cancer however showed disappointing results and the strategy was soon dismissed. In 1996, Mazzaferro et al introduced the Milan criteria, offering liver transplantation to patients diagnosed with limited hepatocellular carcinoma. Since then, liver transplantation for malignant disease is an ongoing subject of preclinical and clinical research. In this context, several aspects must be considered: (1) Given the shortage of deceased-donor organs, long-term overall and disease free survival should be comparable with results obtained in patients transplanted for non-malignant disease; (2) In this regard, living-donor liver transplantation may in selected patients help to solve the ethical dilemma of optimal individual patient treatment vs organ allocation justice; and (3) Ongoing research focusing on perioperative therapy and anti-proliferative immunosuppressive regimens may further reduce tumor recurrence in patients transplanted for malignant disease and thus improve overall survival. The present review gives an overview of current indications and future perspectives of liver transplantation for malignant disease.

Liver transplantation for unresectable neuroendocrine tumor liver metastases

BACKGROUND

Liver transplantation (LT) is performed in selected patients with neuroendocrine hepatic metastases. Survival benefit and the risk of tumor recurrence after LT, also exacerbated by immunosuppressive therapy, remain important clinical issues. Whether patients with particular types of neuroendocrine tumors (NET) benefit more than others is unclear.

METHODS

Bibliographical searches were performed in PubMed for the terms "liver transplantation and neuroendocrine tumors," "liver transplant and neuroendocrine tumors," "liver transplantation and immunosuppressive therapy," "tumor recurrence."

RESULTS

Promising results have been reported for LT for NET metastases with 5-year survival of up to 90 % in patients with well-differentiated gastroenteropancreatic NETs, but only few patients are free of tumor 5 years after LT. Better outcomes have been reported for gastrointestinal tumors than for pancreatic NETs for both survival and risk or recurrence after LT. Selection criteria for LT are limited and include the 2007 Milan Criteria and the 2012 European Neuroendocrine Tumor Society guidelines, including: well-differentiated NET (Ki-67 <10 %), age <55 years, absence of extrahepatic disease, primary tumor removed before transplantation, stable disease for at least 6 months before LT, and <50 % liver involvement.

CONCLUSIONS

LT might be considered in carefully selected patients. The risk of tumor recurrence remains a significant clinical problem after LT, but data focused on immunosuppression issue are lacking, and there are no currently approved strategies for prevention of recurrence or follow-up protocols. Further studies are needed to define universally accepted inclusion criteria, reliable predictors of better outcome, and optimal timing for LT.

Meeting report of the 19th Annual International Congress of the International Liver Transplantation Society (Sydney Convention and Exhibition Centre, Sydney, Australia, June 12-15, 2013)

The International Liver Transplantation Society held its annual meeting from June 12 to 15 in Sydney, Australia. More than 800 registrants attended the congress, which opened with a conference celebrating 50 years of liver transplantation (LT). The program included series of featured symposia, focused topic sessions, and oral and poster presentations. This report is by no means all-inclusive and focuses on specific abstracts on key topics in LT. Similarly to previous reports, this one presents data in the context of the published literature and highlights the current direction of LT.

Zollinger-Ellison syndrome: recent advances and controversies

PURPOSE OF REVIEW

To review the recent advances and current controversies in patients with Zollinger-Ellison syndrome (ZES).

RECENT FINDINGS

Recent advances in the management of ZES include: improved understanding of the pathogenesis of gastrinoma and pancreatic neuroendocrine tumors, new prognostic classification systems, new diagnostic algorithms, more sensitive localization studies, new treatment strategies including improved control of gastric acid secretion and role for surgery, and new approaches to patients with advanced disease. Controversies include: the best approach to a patient with hypergastrinemia suspected of possibly having ZES, the appropriate gastrin assay to use, the role of surgery in patients with ZES, especially those with multiple endocrine neoplasia type 1, and the precise order of therapeutic modalities in the treatment of patients with advanced disease.

SUMMARY

This review updates clinicians regarding important advances and controversies required to optimally diagnose and manage patients with ZES.