Hepatic resection for metastatic gastrointestinal and pancreatic neuroendocrine tumours: outcome and prognostic predictors

Current and emerging anti-angiogenic therapies in gastrointestinal and hepatobiliary cancers

Gastrointestinal tumours are a heterogeneous group of neoplasms that arise in the gastrointestinal tract and hepatobiliary system. Their incidence is rising globally and they currently represent the leading cause of cancer-related mortality worldwide. Anti-angiogenic agents have been incorporated into the treatment armamentarium of most of these malignancies and have improved survival outcomes, most notably in colorectal cancer and hepatocellular carcinoma. New treatment combinations with immunotherapies and other agents have led to unprecedented benefits and are revolutionising patient care. In this review, we detail the mechanisms of action of anti-angiogenic agents and the preclinical rationale underlying their combinations with immunotherapies. We review the clinical evidence supporting their use across all gastrointestinal tumours, with a particular emphasis on colorectal cancer and hepatocellular carcinoma. We discuss available biomarkers of response to these therapies and their utility in routine clinical practice. Finally, we summarise ongoing clinical trials in distinct settings and highlight the preclinical rationale supporting novel combinations.

Multimodal Management of Grade 1 and 2 Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (p-NETs) are rare tumors with a recent growing incidence. In the 2017 WHO classification, p-NETs are classified into well-differentiated (i.e., p-NETs grade 1 to 3) and poorly differentiated neuroendocrine carcinomas (i.e., p-NECs). P-NETs G1 and G2 are often non-functioning tumors, of which the prognosis depends on the metastatic status. In the localized setting, p-NETs should be surgically managed, as no benefit for adjuvant chemotherapy has been demonstrated. Parenchymal sparing resection, including both duodenum and pancreas, are safe procedures in selected patients with reduced endocrine and exocrine long-term dysfunction. When the p-NET is benign or borderline malignant, this surgical option is associated with low rates of severe postoperative morbidity and in-hospital mortality. This narrative review offers comments, tips, and tricks from reviewing the available literature on these different options in order to clarify their indications. We also sum up the overall current data on p-NETs G1 and G2 management.

Targeted Cancer Therapy: What's New in the Field of Neuroendocrine Neoplasms?

Neuroendocrine tumors (NETs) are a heterogeneous family of neoplasms of increasing incidence and high prevalence due to their relatively indolent nature. Their wide anatomic distribution and their characteristic ability to secrete hormonally active substances pose unique challenges for clinical management. They are also characterized by the common expression of somatostatin receptors, a target that has been extremely useful for diagnosis and treatment (i.e., somatostatin analogues (SSAs) and peptide-receptor radionuclide therapy (PRRT)). Chemotherapy is of limited use for NETs of non-pancreatic origin, and the only approved targeted agents for advanced progressive NETs are sunitinib for those of pancreatic origin, and everolimus for lung, gastrointestinal and pancreatic primaries. Despite recent therapeutic achievements, thus, systemic treatment options remain limited. In this review we will discuss the state-of-the-art targeted therapies in the field of NETs, and also future perspectives of novel therapeutic drugs or strategies in clinical development, including recently presented results from randomized trials of yet unapproved antiangiogenic agents (i.e., pazopanib, surufatinib and axitinib), PRRT including both approved radiopharmaceuticals (177Lu-Oxodotreotide) and others in development (177Lu-Edotreotide, 177Lu-Satoreotide Tetraxetan), immunotherapy and other innovative targeted strategies (antibody-drug conjugates, bites,…) that shall soon improve the landscape of personalized treatment options in NET patients.

Heterogeneity of Vascular Endothelial Cells, De Novo Arteriogenesis and Therapeutic Implications in Pancreatic Neuroendocrine Tumors

Arteriogenesis supplies oxygen and nutrients in the tumor microenvironment (TME), which may play an important role in tumor growth and metastasis. Pancreatic neuroendocrine tumors (pNETs) are the second most common pancreatic malignancy and are frequently metastatic on presentation. Nearly a third of pNETs secrete bioactive substances causing debilitating symptoms. Current treatment options for metastatic pNETs are limited. Importantly, these tumors are highly vascularized and heterogeneous neoplasms, in which the heterogeneity of vascular endothelial cells (ECs) and de novo arteriogenesis may be critical for their progression. Current anti-angiogenetic targeted treatments have not shown substantial clinical benefits, and they are poorly tolerated. This review article describes EC heterogeneity and heterogeneous tumor-associated ECs (TAECs) in the TME and emphasizes the concept of de novo arteriogenesis in the TME. The authors also emphasize the challenges of current antiangiogenic therapy in pNETs and discuss the potential of tumor arteriogenesis as a novel therapeutic target. Finally, the authors prospect the clinical potential of targeting the FoxO1-CD36-Notch pathway that is associated with both pNET progression and arteriogenesis and provide insights into the clinical implications of targeting plasticity of cancer stem cells (CSCs) and vascular niche, particularly the arteriolar niche within the TME in pNETs, which will also provide insights into other types of cancer, including breast cancer, lung cancer, and malignant melanoma.

Surgical Approaches to the Management of Neuroendocrine Liver Metastases

Surgical approaches to hepatic metastases occupy an important role in the management of patients with neuroendocrine neoplasms and may have curative or palliative intentions. Resection of hepatic disease with curative intent is the only modality offering potential cure for patients with liver metastases; however, only a minority of patients are eligible. Regardless of resection margin, disease recurrence almost invariably occurs and novel adjuvant/neoadjuvant therapies are mandated to be included within multimodal treatment concepts. Liver transplantation in meticulously selected patients may be associated with excellent outcomes, but unfortunately demands on donated organs limit the wider utilization of this approach.

Treatment options for PNET liver metastases: a systematic review

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are rare pancreatic neoplasms. About 40-80% of patients with PNET are metastatic at presentation, usually involving the liver (40-93%). Liver metastasis represents the most significant prognostic factor. The aim of this study is to present an up-to-date review of treatment options for patients with liver metastases from PNETs.

METHODS

A systematic literature search was performed using the PubMed database to identify all pertinent studies published up to May 2018.

RESULTS

The literature search evaluated all the therapeutic options for patients with liver metastases of PNETs, including surgical treatment, loco-regional therapies, and pharmacological treatment. All the different treatment options showed particular indications in different presentations of liver metastases of PNET. Surgery remains the only potentially curative therapeutic option in patients with PNETs and resectable liver metastases, even if relapse rates are high. Efficacy of medical treatment has increased with advances in targeted therapies, such as everolimus and sunitinib, and the introduction of radiolabeled somatostatin analogs. Several techniques for loco-regional control of metastases are available, including chemo- or radioembolization.

CONCLUSIONS

Treatment of patients with PNET metastases should be multidisciplinary and must be personalized according to the features of individual patients and tumors.

Neuroendocrine liver metastasis: The chance to be cured after liver surgery

BACKGROUND AND OBJECTIVE

Neuroendocrine liver metastasis tumors (NELM) are a heterogeneous group of neoplasms with varied histologic features and a wide range of clinical behaviors. We aimed to identify the fraction of patients cured after liver surgery for NELM.

METHODS

Cure fraction models were used to analyze 376 patients who underwent hepatectomy with curative intent for NELM.

RESULTS

The median and 5-year disease-free survival (DFS) were 4.5 years and 46%, respectively. The probability of being cured from NELM by liver surgery was 44%; the time to cure was 5.1 years. In a multivariable cure model, type of neuroendocrine tumor (NET), grade of tumor differentiation, and rate of liver involvement resulted as independent predictors of cure. The cure fraction for patients with well differentiated NELM from gastrointestinal NET or a functional pancreatic NET, and with <50% of liver-involvement was 95%. Patients who had moderately/poorly differentiated NELM from a non-functional pancreatic NET, and with <50% of liver-involvement was 43%. In the presence of all the three unfavorable prognostic factors (nonfunctional PNET, liver involvement >50%, moderately/poorly differentiation), the cure fraction was 8%.

CONCLUSIONS

Statistical cure after surgery for NELM is possible, and allow for a more accurate prediction of long-term outcome among patients with NELM undergoing liver resection.

The safety and effectiveness of liver resection for breast cancer liver metastases: A systematic review

Breast cancer liver metastases have traditionally been considered incurable and any treatment given therefore palliative. Liver resections for breast cancer metastases are being performed, despite there being no robust evidence for which patients benefit. This review aims to determine the safety and effectiveness of liver resection for breast cancer metastases. A systematic literature review was performed and resulted in 33 papers being assembled for analysis. All papers were case series and data extracted was heterogeneous so a meta-analysis was not possible. Safety outcomes were mortality and morbidity (in hospital and 30-day). Effectiveness outcomes were local recurrence, re-hepatectomy, survival (months), 1-, 2-, 3-, 5- year overall survival rate (%), disease free survival (months) and 1-, 2-, 3-, 5- year disease free survival rate (%). Overall median figures were calculated using unweighted median data given in each paper. Results demonstrated that mortality was low across all studies with a median of 0% and a maximum of 5.9%. The median morbidity rate was 15%. Overall survival was a median of 35.1 months and a median 1-, 2-, 3- and 5-year survival of 84.55%, 71.4%, 52.85% and 33% respectively. Median disease free survival was 21.5 months with a 3- and 5-year median disease free survival of 36% and 18%. Whilst the results demonstrate seemingly satisfactory levels of overall survival and disease free survival, the data are of poor quality with multiple confounding variables and small study populations. Recommendations are for extensive pilot and feasibility work with the ultimate aim of conducting a large pragmatic randomised control trial to accurately determine which patients benefit from liver resection for breast cancer liver metastases.

Long term results of hepatic resection or orthotopic liver transplantation in patients with liver metastases from gastrointestinal neuroendocrine tumors

Hepatic metastases are one of the most important prognostic factors for survival among patients affected by gastrointestinal neuroendocrine tumors (NETs). The present study aims to evaluate the impact of surgery, including hepatic resection or orthotopic liver transplantation (OLT), on the outcome of patients affected by hepatic metastases from NETs, in terms of overall survival (OS). In this multicentric retrospective study, data was collected on 26 patients, who underwent surgery for hepatic metastases from NETs in two Italian University Clinics between January 1990 and December 2012; of which, 22 patients underwent hepatic resective surgery and 4 patients OLT. Hepatic metastases were synchronous in the 53.8% of cases and metachronous in the 46.2% of cases. The median number of resected hepatic metastases was 3. Surgical radicalness (R0) was reached in the 84.6% of cases. In total, 57.7% of patients had a recurrence, 66.7% of which were intra- and 33.3% extra-hepatic. The OS of patients that underwent hepatic resections and OLT was 44.9% [95% confidence interval (CI95), 26.0-77.7%] and 50% (CI95, 12.5-100.0%) at 5 years, respectively. Although the data regarding the survival of patients receiving surgery for hepatic metastases from NETs are encouraging, randomized clinical trials are necessary to more adequately evaluate the effect of surgery on survival of this group of patients.

Surgical management of neuroendocrine tumors

During the last decades an increase in the incidence of neuroendocrine tumors (NETs) was observed. Gastroenteropancreatic NETs represent the majority of NETs. Compared with their epithelial counterpart they usually have a more indolent behaviour and surgical resection improves survival. Tumor diameter is one of the main parameter in the decision making process for nonfunctioning forms. Generally, small lesions can be treated conservatively whereas larger tumors should be treated with standard surgical resection and lymphadenectomy. Functioning tumors should be resected regardless the dimension of the lesion. Locally advanced and metastatic disease should be also treated with extended resections, keeping in consideration the grading, size, Ki67, and presence of extra-abdominal disease. In the case of metastases the panel of operative treatment includes resection, ablation, up to liver transplantation.

When should a liver resection be performed in patients with liver metastases from neuroendocrine tumours? A systematic review with practice recommendations

AIM

To determine the benefits and risks of hepatic resection versus non-resectional liver-directed treatments in patients with potentially resectable neuroendocrine liver metastases.

METHODS

A systematic review identified 1594 reports which alluded to a possible liver resection for neuroendocrine tumour metastases, of which 38 reports (all retrospective), comprising 3425 patients, were relevant.

RESULTS

Thirty studies reported resection alone, and 16 studies reported overall survival (OS). Only two studies addressed quality-of-life (QoL) issues. Five-year overall survival was reported at 41-100%, whereas 5-year progression-free survival (PFS) was 5-54%. We identified no robust evidence that a liver resection was superior to any other liver-directed therapies in improving OS or PFS. There was no evidence to support the use of a R2 resection (debulking), with or without tumour ablation, to improve either OS or QoL. There was little evidence to guide sequencing of surgery for patients presenting in Stage IV with resectable disease, and none to support a resection of asymptomatic primary tumours in the presence of non-resectable liver metastases.

CONCLUSION

Low-level recommendations are offered to assist in the management of patients with neuroendocrine liver metastases, along with recommendations for future studies.

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.

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.

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.

Surgical treatment and survival in patients with liver metastases from neuroendocrine tumors: a meta-analysis of observational studies

Introduction. The role of hepatic resection in patients with liver metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs) is still poorly defined. Therefore, we examined the results obtained with surgical resection and other locoregional or systemic therapies by reviewing the recent literature on this topic. We performed the meta-analysis for comparing surgical resection of hepatic metastases with other treatments. Materials and Methods. In this systematic review and meta-analysis of observational studies, the literature search was undertaken between 1990 and 2012 looking for studies evaluating the different survivals between patients treated with surgical resection of hepatic metastases and with other surgical or nonsurgical therapies. The studies were evaluated for quality, publication bias, and heterogeneity. Pooled hazard ratio (HR) estimates and 95% confidence intervals (CI.95) were calculated using fixed-effects model. Results. We selected six studies in the review, five of which were suitable for meta-analysis. We found a significant longer survival in patients treated with hepatic resection than embolisation HR 0.34 (CI.95 0.21-0.55) or all other nonsurgical treatments HR 0.45 (CI.95 0.34-0.60). Only one study compared surgical resection with liver transplantation and meta-analysis was not feasible. Conclusions. Our meta-analysis provides evidence supporting the hypothesis that hepatic resection increases overall survival in patients with liver metastases from GEP-NETs. Further randomized clinical trials are needed to confirm these findings and it would be desirable to identify new markers to properly select patients for surgical treatment.

Surgical resection of hepatic metastases from neuroendocrine neoplasms: a systematic review

BACKGROUND

Neuroendocrine tumours (NET) most commonly metastasize to the liver. Hepatic resection of NET hepatic metastases (NETHM) has been shown to improve symptomology and survival.

METHODS

A systematic review of clinical studies before September 2010 was performed to examine the efficacy of hepatic resection for NETHM. As a secondary end-point, the impact of treatment on safety and symptomology were determined and prognostic variables were identified. The quality of each study was also assessed using predefined criteria incorporating 9 characteristics. Clinical outcome was synthesized through a narrative review with full tabulation of results of all included studies.

RESULTS

Twenty-nine included reported survival outcomes with a median 3-, 5- and 10-year overall survival of 83% (range, 63-100%), 70.5% (range, 31-100%), and 42% (range, 0-100%), respectively. The median progression-free survival (PFS) was 21 months (range, 13-46 months) and median 1-,3-,5- and 10-year PFS of 63% (range, 50-80 %), 32% (range, 24-69%), 29% (range, 6-66%) and 1% (range, 0-11%), respectively. Poor histologic grade, extra-hepatic disease and a macroscopically incomplete resection were associated with a poor prognosis. Studies reported a median rate of symptomatic relief from surgery in 95% of patients (range, 50-100%).

CONCLUSION

Hepatic resection for NETHM provides symptomatic benefit and is associated with favourable survival outcomes although the majority of patients invariably develop disease progression.

Surgical treatment of liver metastases in neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) are a distinctive entity, and nearly 10% of patients already have liver metastases at presentation. The management of neuroendocrine liver metastases (NEN-LM) is complex with differing patterns of metastatic presentation. An aggressive approach should be used to resect the primary tumor, to remove regional lymph nodes, and to resect or treat appropriate distant metastases (including liver tumors). Despite having an indolent course, NENs have a significantly reduced survival when liver metastases are untreated. Though a wide range of therapies are now available with a multimodal approach to the treatment, surgical treatment offers the only chance for a significant survival prolongation and/or improvement of symptoms and quality of life. A review of the existing surgical modalities for NEN-LM is discussed in this paper.

Surgical treatment of neuroendocrine liver metastases

Management of Neuroendocrine liver metastases (NELM) is challenging. The presence of NELM worsens survival outcome and almost 10% of all liver metastases are neuroendocrine in origin. There is no firm consensus on the optimal treatment strategy for NELM. A systematic search of the PubMed database was performed from 1995-2010, to collate the current evidence and formulate a sound management algorithm. There are 22 case series with a total of 793 patients who had undergone surgery for NELM. The overall survival ranges from 46-86% at 5 years, 35-79% at 10 years, and the median survival ranges from 52-123 months. After successful cytoreductive surgery, the mean duration of symptom reduction is between 16-26 months, and the 5-year recurrence/progression rate ranges from 59-76%. Five studies evaluated the efficacy of a combination cytoreductive strategy reporting survival rate of ranging from 83% at 3 years to 50% at 10 years. To date, there is no level 1 evidence comparing surgery versus other liver-directed treatment options for NELM. An aggressive surgical approach, including combination with additional liver-directed procedures is recommended as it leads to long-term survival, significant long-term palliation, and a good quality of life. A multidisciplinary approach should be established as the platform for decision making.

A multimodal approach to the management of neuroendocrine tumour liver metastases

Neuroendocrine tumours (NETs) are often indolent malignancies that commonly present with metastatic disease in the liver. Surgical, locoregional, and systemic treatment modalities are reviewed. A multidisciplinary approach to patient care is suggested to ensure all therapeutic options explored.

Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs)

These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.

Role of everolimus in pancreatic neuroendocrine tumors

Survival from pancreatic neuroendocrine tumors has not improved over the past two decades and, until recently, streptozocin was the last therapeutic agent approved for this malignancy. Everolimus blocks mTOR, which plays an integral role in cell growth, mitosis and angiogenesis. Abnormal PI3K-Akt/PKB-mTOR pathway signaling has been implicated in the pathogenesis of pancreatic neuroendocrine tumors. In a Phase III study, patients with low- and intermediate-grade advanced pancreatic neuroendocrine tumors were randomized to receive everolimus 10 mg/day or placebo. Median progression-free survival was significantly greater in patients treated with everolimus than placebo - 11 versus 4.6 months - and drug-related adverse events were consistent with the known side-effect profile of everolimus. Everolimus represents a significant treatment development for pancreatic neuroendocrine tumors.

Multimodal management of neuroendocrine liver metastases

BACKGROUND

The incidence of neuroendocrine tumours (NET) has increased over the past three decades. Hepatic metastases which occur in up to 75% of NET patients significantly worsen their prognosis. New imaging techniques with increasing sensitivity enabling tumour detection at an early stage have been developed. The treatment encompasses a panel of surgical and non-surgical modalities.

METHODS

This article reviews the published literature related to management of hepatic neuroendocrine metastases.

RESULTS

Abdominal computer tomography, magnetic resonance tomography and somatostatin receptor scintigraphy are widely accepted imaging modalities. Hepatic resection is the only potentially curative treatment. Liver transplantation is justified in highly selected patients. Liver-directed interventional techniques and locally ablative measures offer effective palliation. Promising novel therapeutic options offering targeted approaches are under evaluation.

CONCLUSIONS

The treatment of neuroendocrine liver metastases still needs to be standardized. Management in centres of expertise should be strongly encouraged in order to enable a multidisciplinary approach and personalized treatment. Development of molecular prognostic factors to select treatment according to patient risk should be attempted.

Surgical management of liver metastases from gastrointestinal endocrine tumors

Liver metastases from endocrine tumors can reduce 5-year survival from 90% to 40% and, in cases of functional gastrointestinal endocrine tumors, lead to a carcinoid syndrome. Complete resection of cancerous disease should be considered in all cases. Indeed, after hepatectomy, prolonged survival (41-86% at five years) can be achieved, with low rates of surgery-related mortality (0-6.7%). Extended liver resection is required in most cases. Percutaneous portal embolization increases the volumetric feasibility of resection, and sequential hepatectomy techniques enable a two-stage resection of both bilobar metastases and the primary tumor. For carcinoid syndrome that does not respond to medical therapy, incomplete resection of liver metastases, by reducing tumor volume, may be indicated to reduce symptoms and halt the progression of carcinoid heart disease. In cases of non-resectable liver metastases in selected patients, liver transplantation can lead to 5-year survival rates as high as 77%.

Reoperative surgery for the Zollinger-Ellison syndrome

It is clear that a properly performed initial operation is the key to success in the management of a patient with ZES. However, reoperation is frequently a consideration in the management of patients with ZES because high rates of persistent and recurrent disease are manifest even with modern imaging and surgical approaches. In carefully selected patients, reoperation can result in durable biochemical cure and improved survival and should be considered. A thorough knowledge of the natural history of the sporadic form of ZES and ZES in the context of MEN-1, patterns of presentation, and sites of metastases are necessary to achieve the best outcome in patients with this unusual disease.

[Indications and operative procedures for neuroendocrine liver metastases]

Neuroendocrine malignancies encompass a variety of tumors that differ considerably in origin, hormonal activity, and biological behavior. Because of their rarity most therapeutic recommendations have been based on limited evidence from small retrospective series observing miscellaneous patient cohorts. Only in recent years proposals for TNM and histological grading systems have been elaborated that allow further stratification of patients suffering from these tumors. Especially patients with well and moderately differentiated neuroendocrine malignancies benefit from resection of liver metastases, improving the 5-year survival rate from <50% to 80%. Orthotopic liver transplantation can likewise improve survival in carefully selected patients. New developments in imaging modalities, intensive care treatment, and in liver surgery itself have broadened the selection of potentially resectable tumors.