Liver transplantation and multivisceral transplantation in the management of patients with advanced neuroendocrine tumours

Developments in interventional management of hepatic metastases from neuroendocrine tumours

Neuroendocrine tumours commonly metastasise to the liver, particularly those arising from the intestinal tract and pancreas. Whilst surgery offers the only approach with intent to cure, the vast majority of patients with neuroendocrine liver metastases are ineligible. Liver-directed interventional therapies seek to exploit the patho-anatomy of the blood supply of hepatic metastases to deliver therapy to liver deposits. This may involve percutaneous ablation, bland embolization, or the selective infusion of chemotherapeutics, targeted agents or radiolabelled embolic material. Retrospective case series evidence has characterised objective response rates, disease control rates, and longer-term outcomes associated with each approach. Recent advances in this field include ongoing comparative trials of different techniques, but more importantly, combinations of interventional liver-directed therapies and other systemic therapy in multimodal treatment concepts.

Transplant oncology: multivisceral transplantation for neuroendocrine tumor and liver metastasis

PURPOSE OF REVIEW

Neuroendocrine tumor (NET) liver metastatic lesions are often multiple and found to be unresectable. Rationale of multivisceral transplantation (MVT: liver-pancreas-intestine transplantation) include radical and complete resection of primary, visible and invisible metastatic tumors by removing all abdominal organs and the lymphatic system. This review aims to describe the concept of MVT for NET and neuroendocrine liver metastasis (NELM), patient selection, timing of MVT, and posttransplant outcomes and management.

RECENT FINDINGS

Although indication criteria of MVT for NET vary between transplant centers, the Milan-NET criteria for liver transplant are often applied to MVT candidates. Extra-abdominal tumors such as lung and/or bone lesions should be ruled out prior to MVT. Histology should be confirmed as low-grade (G1/G2). Ki-67 should be also checked to confirm biologic features. Timing of MVT remains controversial, whereas many experts recommend 6 months of disease stability prior to MVT.

SUMMARY

Although MVT would not be a standard therapy because of limited access to MVT centers, benefit of MVT should be recognized, which includes its potential ability to better achieve curative resection of disseminated tumors in the abdominal cavity. Early referral of difficult cases to MVT centers should be considered before palliative best supportive cares.

Transplantation for metastatic liver disease

The liver is a common site of metastases from many cancers, particularly those originating in the gastrointestinal tract. Liver transplantation is an uncommonly used but promising and at times controversial treatment option for neuroendocrine and colorectal liver metastases. Transplantation with meticulous patient selection has been associated with excellent long-term outcomes in individuals with neuroendocrine liver metastases, but questions remain regarding the role of transplantation in those who could also be eligible for hepatectomy, the role of neoadjuvant/adjuvant treatments in minimising recurrence, and the optimal timing of the procedure. A prospective pilot study of liver transplantation for unresectable colorectal liver metastases that reported a 5-year overall survival rate of 60% reinvigorated interest in this area following initially dismal outcomes. This has been followed by larger studies, and prospective trials are ongoing to quantify the potential benefits of liver transplantation over palliative chemotherapy. This review provides a critical summary of currently available knowledge on liver transplantation for neuroendocrine and colorectal liver metastases, and highlights avenues for further study to address gaps in the evidence base.

First Report With Medium-term Follow-up of Intestinal Transplantation for Advanced and Recurrent Nonresectable Pseudomyxoma Peritonei

OBJECTIVE

To report our experience with the combination of radical surgical excision and intestinal transplantation in patients with recurrent pseudomyxoma peritonei (PMP) not amenable to further cytoreductive surgery (CRS).

BACKGROUND

CRS and heated intraoperative peritoneal chemotherapy are effective treatments for many patients with PMP. In patients with extensive small bowel involvement or nonresectable recurrence, disease progression results in small bowel obstruction, nutritional failure, and fistulation, with resulting abdominal wall failure.

METHODS

Between 2013 and 2022, patients with PMP who had a nutritional failure and were not suitable for further CRS underwent radical debulking and intestinal transplantation at our centre.

RESULTS

Fifteen patients underwent radical exenteration of affected intra-abdominal organs and transplantation adapted according to the individual case. Eight patients had isolated small bowel transplantation and 7 patients underwent modified multivisceral transplantation. In addition, in 7 patients with significant abdominal wall tumor involvement, a full-thickness vascularized abdominal wall transplant was performed. Two of the 15 patients died within 90 days due to surgically related complications. Actuarial 1-year and 5-year patient survivals were 79% and 55%, respectively. The majority of the patients had significant improvement in quality of life after transplantation. Progression/recurrence of disease was detected in 91% of patients followed up for more than 6 months.

CONCLUSION

Intestinal/multivisceral transplantation enables a more radical approach to the management of PMP than can be achieved with conventional surgical methods and is suitable for patients for whom there is no conventional surgical option. This complex surgical intervention requires the combined skills of both peritoneal malignancy and transplant teams.

Liver transplantation in gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors are part of a heterogeneous group of tumors located in organs such as the gastrointestinal tract (GIT), lungs, thymus, thyroid, and adrenal glands. The most prevalent sites are the small intestine, cecal appendix, and pancreas. More than 50% of these tumors are associated with metastases at the time of diagnosis. Neuroendocrine tumors are classified according to the degree of cell differentiation and the histopathological proliferation index of the lesion. Neuroendocrine tumors can be well differentiated or poorly differentiated. G3 tumors are characterized by Ki-67 expression greater than 20% and can be either well differentiated (G3 NET) or poorly differentiated (G3 NEC). Neuroendocrine carcinoma (NEC G3) is subdivided into small-cell and large-cell types. When neuroendocrine tumors present clinical and compressive symptoms, carcinoid syndrome is evident. Carcinoid syndrome occurs when the tumor produces neuroendocrine mediators that cannot be metabolized by the liver due to either the size of the tumor or their secretion by the liver itself. Several therapeutic strategies have been described for the treatment of metastatic neuroendocrine tumors, including curative or palliative surgical approaches, peptide receptor radionuclide therapy, percutaneous therapy, systemic chemotherapy, and radiotherapy. Liver surgery is the only approach that can offer a cure for metastatic patients. Liver metastases must be completely resected, and in this context, orthotopic liver transplantation has gained prominence for yielding very promising outcomes in selected cases. The aim of this study is to review the literature on OLT as a form of treatment with curative intent for patients with gastroenteropancreatic neuroendocrine tumors with liver metastasis.

Long-term outcomes of resection versus transplantation for neuroendocrine liver metastases meeting the Milan criteria

Liver resection (LR) is considered the treatment of choice for resectable neuroendocrine liver metastases (NELM), while liver transplantation (LT) is currently reserved for highly selected unresectable patients. We retrospectively analyzed data from consecutive patients undergoing either curative resection or transplantation for liver-only NELM meeting Milan criteria at a single center between 1984 and 2019. Patients who fit Milan criteria were 48 in the transplantation group and 56 in the resection group. After a median follow-up of 158 months for the transplantation group and 126 for the resection group, the 10-year survival rate was 93% for transplantation and 75% for resection (p = .007). The 10-year disease-free survival rate was 52% for transplantation and 18% for resection (p < .001). Transplantation was associated with improved survival at univariate analysis. The median disease-free interval between surgery and recurrence was 78 months for transplantation vs. 24 months for resection (p < .001). The transplantation group had more multisite recurrences (12/25, 48% vs. 5/42, 12% in the resection group, p = .001), while most recurrences in the resection group were intra-hepatic (37/42, 88%, versus 2/25, 8% in the transplantation group). In conclusion, LT was associated with improved survival outcomes in NELM meeting the Milan criteria compared with LR.

[Gastroenteropancreatic neuroendocrine neoplasms-Heterogeneity, management and perspectives of treatment and research]

The term neuroendocrine neoplasms (NEN) encompasses a molecularly and biologically very heterogeneous group of tumors, which have in common their origin in neuroendocrine cells. The also very heterogeneous subgroup of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) is the best classified and investigated group. This article provides a systematic review of the current classification, diagnostics and treatment options of GEP-NEN. In order to achieve a better overview, it was consciously decided not to use an approach based on the primary localization. Instead, a thematic organization according to classification, clinical phenotype, diagnostics and treatment was chosen.

Neuroendocrine liver metastases: a contemporary review of treatment strategies

Well-differentiated neuroendocrine tumors (NETs) are globally increasing in prevalence and the liver is the most common site of metastasis. Neuroendocrine liver metastases (NELM) are heterogeneous in clinical presentation and prognosis. Fortunately, recent advances in diagnostic techniques and therapeutic strategies have improved the multidisciplinary management of this challenging condition. When feasible, surgical resection of NELM offers the best long-term outcomes. General indications for hepatic resection include performance status acceptable for major liver surgery, grade 1 or 2 tumors, absence of extrahepatic disease, adequate size and function of future liver remnant, and feasibility of resecting >90% of metastases. Adjunct therapies including concomitant liver ablation are generally safe when used appropriately and may expand the number of patients eligible for surgery. Among patients with synchronous resectable NELM, resection of the primary either in a staged or combined fashion is recommended. For patients who are not surgical candidates, liver-directed therapies such as transarterial embolization, chemoembolization, and radioembolization can provide locoregional control and improve symptoms of carcinoid syndrome. Multiple systemic therapy options also exist for patients with advanced or progressive disease. Ongoing research efforts are needed to identify novel biomarkers that will define the optimal indications for and sequencing of treatments to be delivered in a personalized fashion.

Short- and long-term outcomes of surgery for colorectal and non-colorectal liver metastasis: a report from a single center in the Baltic country

BACKGROUND

The liver is a major target organ for metastases of various types of cancers. Surgery is a well-established option for colorectal liver metastases (CRLM). Regarding the improved surgical and anesthetic techniques, the safety of liver resection has increased. Consequently, the interest in the surgical management of non-colorectal liver metastases (non-CRLM) has gained significant attention. Therefore, this study was designed to investigate the surgical treatment outcomes for non-CRLM and to compare it with an outcome of CRLM in a tertiary care center in the Baltic country-Lithuania.

METHODS

We retrospectively analyzed data from all patients who underwent liver resection for CRLM or non-CRLM between 2010 and 2017 in a tertiary care center-Vilnius University hospital Santaros Clinics. Demographic and metastasis characteristics, as well as disease-free and overall survival, were compared between the study groups.

RESULTS

In total, 149 patients were included in the study. Patients in the CRLM group were older (63.2 ± 1.01 vs 54.1 ± 1.8 years, p < 0.001) and mainly predominant by males. Overall postoperative morbidity rate (16.3% vs 9.8%, p = 0.402) and major complications rate (10% vs 7.8%, p = 0.704) after liver resection for CRLM and non-CRLM was similar. Kaplan-Meier analysis showed higher disease-free survival in the CRLM group with 89.4% vs 76.5% and 64.9% vs 31.4% survival rates at 1 and 3 years, respectively (p = 0.042), although overall survival was not different between the CRLM and non-CRLM groups with 89.4% vs 78.4% and 72.0% vs 46.1% survival rates at 1 and 3 years, respectively (p = 0.300).

CONCLUSIONS

In this study, we confirmed comparable short- and long-term outcomes after liver resection for CRLM and non-CRLM. Surgical resection should be encouraged as an option in well-selected patients with non-CRLM.

Primary hepatic neuroendocrine carcinoma coexisting with distal cholangiocarcinoma: A case report and review of the literature

INTRODUCTION

Although primary hepatic neuroendocrine carcinomas, whose prognostic mechanisms remain unclear, are rare, coexistence of neuroendocrine carcinomas and other tumors is rarer. In this report, we describe a unique case of coexistence between primary hepatic neuroendocrine carcinoma and a distal cholangiocarcinoma in the pancreas.

PATIENT CONCERNS

A 64-year-old woman with a history of diabetes, but none of hepatitis, was admitted to hospital because of intermittent epigastric distension and pain discomfort for more than 1 month aggravated 1 day. A contrast-enhanced computed tomography (CT) scan of the upper abdomen and abdominal magnetic resonance imaging (MRI) revealed a thickening of the bile duct wall in the middle and lower segment of common bile duct and the corresponding lumen is narrow and low-density tumors with ring enhancement (1.83 cm × 1.9 cm) in lobi hepatis dexte.

DIAGNOSIS

Primary neuroendocrine carcinoma of the liver was diagnosed to be coexisting with a distal cholangiocarcinoma, which had invaded the pancreas. Immunohistochemical examination revealed that the neoplastic cells strongly expressed chromogranin A, synaptophysin, and CD56 proteins. The tumor cells did not express HepPar-1, glypican-3, S-100, CK7, and CK19 in the liver tumor. A distal bile duct in pancreatic tissues shows the characteristics of typical bile duct carcinoma, as an invasion of carcinoma is also seen in the pancreatic tissues. Gastrointestinal endoscopy, chest and abdominal CT, abdominal MRI, and positron emission tomography (PET)-CT were used to exclude metastatic neuroendocrine tumors of the liver.

INTERVENTIONS

Resection of the pancreas-duodenum, the right anterior lobe of the liver, and regional lymph nodes was performed in patients.

OUTCOMES

The patient had survived for 5 months after the operation.

CONCLUSION

A unique case of a coexistence of primary hepatic neuroendocrine carcinoma and a distal cholangiocarcinoma, which had invaded the pancreas. No treatment guidelines are established for the treatment of the unique case.

Pathogenesis and Clinical Management of Mesenteric Fibrosis in Small Intestinal Neuroendocine Neoplasms: A Systematic Review

Mesenteric fibrosis (MF) constitutes an underrecognized sequela in patients with small intestinal neuroendocrine neoplasms (SI-NENs), often complicating the disease clinical course. The aim of the present systematic review, carried out by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, is to provide an update in evolving aspects of MF pathogenesis and its clinical management in SI-NENs. Complex and dynamic interactions are present in the microenvironment of tumor deposits in the mesentery. Serotonin, as well as the signaling pathways of certain growth factors play a pivotal, yet not fully elucidated role in the pathogenesis of MF. Clinically, MF often results in significant morbidity by causing either acute complications, such as intestinal obstruction and/or acute ischemia or more chronic conditions involving abdominal pain, venous stasis, malabsorption and malnutrition. Surgical resection in patients with locoregional disease only or symptomatic distant stage disease, as well as palliative minimally invasive interventions in advanced inoperable cases seem clinically meaningful, whereas currently available systemic and/or targeted treatments do not unequivocally affect the development of MF in SI-NENs. Increased awareness and improved understanding of the molecular pathogenesis of MF in SI-NENs may provide better diagnostic and predictive tools for its timely recognition and intervention and also facilitates the development of agents targeting MF.

Surgical management of pancreatic neuroendocrine liver metastases

Pancreatic neuroendocrine tumors (PNET) are a heterogeneous group of neoplasms that vary in their clinical presentation, behavior and prognosis. The most common site of metastasis is the liver. Surgical resection of neuroendocrine liver metastases (NELM) is thought to afford the best long-term outcomes when feasible. Initial preoperative workup should include surveillance for carcinoid syndrome, screening for evidence of liver insufficiency, and performance of imaging specific to neuroendocrine tumors such as a somatostatin receptor positron emission tomography scan. Standard surgical principles apply to hepatic surgery for NELM, namely prioritizing low central venous pressure anesthesia, minimizing blood loss, knowledge of liver anatomy, generous use of intraoperative ultrasound, as well as safe parenchymal transection techniques and practices to avoid bile leakage. Knowledge of established prognostic factors may assist with patient selection, which is important for optimizing short- and long-term outcomes of hepatic resection. Adjunct therapies such as concomitant liver ablation are used frequently and are generally safe when used appropriately. For patients with synchronous resectable NELM, resection of the primary either in a staged or combined fashion is recommended. Primary tumor resection in the setting of unresectable metastatic disease is more controversial, however generally recommended if morbidity is acceptable. For patients who are not surgical candidates, due to either patient performance status or burden of liver disease, several liver-directed therapies such as transarterial embolization, chemoembolization, and radioembolization are available to assist with locoregional control, extend progression-free survival (PFS), and improve symptoms of carcinoid syndrome. Multiple systemic therapy options exist for patients with metastatic PNET which are often prioritized for those patients with advanced or progressive disease. A systematic approach in a multi-disciplinary setting is likely to result in the best long-term outcomes for patients with pancreatic NELM. Ongoing research is needed to determine the optimal patient selection for hepatic surgery as well as the ideal treatment sequencing for those patients with NELM.

Neuroendocrine Neoplasms of the Small Bowel and Pancreas

The traditionally promulgated perspectives of neuroendocrine neoplasms (NEN) as rare, indolent tumours are blunt and have been outdated for the last 2 decades. Clear increments in their incidence over the past decades render them increasingly clinically relevant, and at initial diagnosis many present with nodal and/or distant metastases (notably hepatic). The molecular pathogenesis of these tumours is increasingly yet incompletely understood. Those arising from the small bowel (SB) or pancreas typically occur sporadically; the latter may occur within the context of hereditary tumour predisposition syndromes. NENs can also be associated with endocrinopathy of hormonal hypersecretion. Tangible advances in the development of novel biomarkers, functional imaging modalities and therapy are especially applicable to this sub-set of tumours. The management of SB and pancreatic neuroendocrine tumours (NET) may be challenging, and often comprises a multidisciplinary approach wherein surgical, medical, interventional radiological and radiotherapeutic modalities are implemented. This review provides a comprehensive overview of the epidemiology, pathophysiology, diagnosis and treatment of SB and pancreatic NETs. Moreover, we provide an outlook of the future in these tumour types which will include the development of precision oncology frameworks for individualised therapy, multi-analyte predictive biomarkers, artificial intelligence-derived clinical decision support tools and elucidation of the role of the microbiome in NEN development and clinical behaviour.

Survival comparison between primary hepatic neuroendocrine neoplasms and primary pancreatic neuroendocrine neoplasms and the analysis on prognosis-related factors

BACKGROUND

Primary hepatic neuroendocrine neoplasms (PHNENs) are extremely rare and few articles have compared the prognosis of PHNENs with other neuroendocrine neoplasms (NENs). This study aimed to investigate the different prognosis between PHNENs and pancreatic NEN (PanNENs) and evaluate the relevant prognosis-related factors.

METHODS

From January 2012 to October 2016, a total of 44 NENs patients were enrolled and divided into two groups according to the primary tumor location which were named group PHNENs (liver; n = 12) and group PanNENs (pancreas; n = 32). Demographic, clinical characteristics and survival data were compared between the two groups with Kaplan-Meier method and log-rank tests. Prognostic factors were analyzed using the Cox regression model.

RESULTS

The overall survival of group PHNENs and group PanNENs were 25.4 ± 6.7 months and 39.8 ± 3.7 months, respectively (P = 0.037). The cumulative survival of group PanNENs was significantly higher than that of group PHNENs (P = 0.029). Univariate analysis revealed that sex, albumin, total bilirubin, total bile acid, aspartate aminotransferase, alkaline phosphatase, α-fetoprotein and carbohydrate antigen 19-9, histological types, treatments and primary tumor site were the prognostic factors. Further multivariate analysis indicated that albumin (P = 0.008), histological types NEC (P = 0.035) and treatments (P = 0.005) were the independent prognostic factors. Based on the histological types, the cumulative survival of patients with well-differentiated neuroendocrine tumor was significant higher than that of patients with poorly differentiated neuroendocrine carcinoma in group PHNENs (P = 0.022), but not in group PanNENs (P > 0.05). According to the different treatments, patients who received surgery had significantly higher cumulative survival than those with conservative treatment in both groups (P < 0.05).

CONCLUSIONS

PHNENs have lower survival compared to PanNENs. Histological types and treatments affect the prognosis. Surgical resection still remains the first line of treatment for resectable lesions and can significantly improve the survival.

Non-Pharmacological Therapeutic Options for Liver Metastases in Advanced Neuroendocrine Tumors

The incidence of liver metastasis in digestive neuroendocrine tumors is high. Their presence appears as an important prognostic factor in terms of quality of life and survival. These tumors may be symptomatic because of the tumor burden itself and/or the hormonal hyper-secretion induced by the tumor. Surgery is the treatment of choice for resectable tumors and metastasis. Nevertheless, surgery is only possible in a small number of cases. The management of non-resectable liver metastasis is a challenge. The literature is rich but consists predominantly in small retrospective series with a low level of proof. Thus, the choice of one technique over another could be difficult. Local ablative techniques (radiofrequency) or trans-catheter intra-arterial liver-directed treatments (hepatic artery embolization, chemo-embolization, and radio-embolization) are frequently considered for liver metastasis. In the present review, we focus on these different therapeutic approaches in advanced neuroendocrine tumors, results (clinical and radiological), and overall efficacy, and summarize recommendations to help physicians in their clinical practice.

Liver re-transplantation for donor-derived neuroendocrine tumor: A case report

BACKGROUND

Donor-origin cancer is a well-recognized but rare complication after liver transplantation (LT). The rise in the use of extended criteria donors due to the current shortage of organs increases the risk. Data on donor-origin neuroendocrine neoplasms (NENs) and the most appropriate treatment are scarce. Here, we report a case of a patient who developed a NEN confined to the liver after LT and was treated with liver re-transplantation (re-LT).

CASE SUMMARY

A 49-year-old man with no other medical co-morbidities underwent LT in 2013 for alcoholic liver cirrhosis. The donor was a 73-year-old female with no known malignancies. Early after LT, a hypoechogenic (15 mm) lesion was detected in the left hepatic lobe on abdominal ultrasound. The lesion was stable for next 11 mo, when abdominal magnetic resonance identified two hypovascular lesions (20 and 11 mm) with atypical enhancement pattern. Follow-up abdominal ultrasound revealed no new lesions for the next 2.5 years, when magnetic resonance showed a progression in size and number of lesions, also confirmed by abdominal computed tomography. Liver biopsy proved a well-differentiated NEN. Genetic analysis of the NEN confirmed donor origin of the neoplasm. As NEN was confined to liver graft only, in 2018, the patient underwent his second LT. At 12 mo after re-LT the patient is well with no signs of NEN dissemination.

CONCLUSION

The benefits of graft explantation should be weighed against the risks of re-LT and the likelihood of NEN dissemination beyond the graft.

Liver transplantation in patients with liver metastases from neuroendocrine tumors

The prevalence of metastatic disease in neuroendocrine tumors (NETs) is very high (60-80%) and cancer-related death among these patients is generally due to metastatic disease. Numerous treatment options for cure and disease control have been investigated for patients with neuroendocrine liver metastases (NELM). Despite the success of liver directed therapy on slowing tumor progression and palliating symptoms, the chance of being cured by liver resection is 40-50% and only roughly 20% of patients have potentially resectable disease. As such, there has been interest in liver transplantation (LT) as a potentially curative option for patients with unresectable disease. Several criteria have been proposed in order to balance long-term outcomes of patients with NELM and the problem of organ shortage including the Milan-NET criteria, the UNOS criteria and the ENETS guidelines. In the most representative studies, recurrence rate after LT has ranged from 30% to 60% with a 5-year OS ranging from 50% to 97%. This large variability is due to the retrospective nature of the studies available, which used different inclusion criteria. As such, outcomes and the prognostic factors associated with LT for NELM warrant further investigation.