Management of advanced neuroendocrine tumors with hepatic metastasis

The efficacy of everolimus and sunitinib in patients with sporadic or germline mutated metastatic pancreatic neuroendocrine tumors

Background

Hyperactivation of mTOR pathway and angiogenesis have been implicated in the pathogenesis of neuroendocrine tumors (NETs). Everolimus, an oral inhibitor of mTOR, and sunitinib, an antiangiogenic drug, are effective targeted therapies approved to treat locally advanced/metastatic pancreatic neuroendocrine tumors (pNETs). Most pNETs are sporadic and mutations in genes involved directly or indirectly in mTOR pathway regulation have been implicated, including somatic mutation in MEN1 in 44% of cases. About 10% of pNETs can be part of hereditary syndromes, e.g., multiple endocrine neoplasia type 1 (MEN1) and Von-Hippel Lindau (VHL), and these patients are underrepresented in pivotal phase III trials. We hypothesized that everolimus would be particularly effective in patients with MEN1-associated pNETs. Likewise, we inferred that sunitinib would also be beneficial to patients with VHL-associated pNETs.

Methods

We conducted a multicenter retrospective and comparative study to assess the efficacy of everolimus and/or sunitinib in a cohort of patients with advanced pNETs with or without known MEN1 or VHL syndrome. The evaluation of the germline mutational status of VHL and MEN1 genes was retrospectively collected from the medical records. The primary endpoints were progression free survival (PFS) and time to treatment failure (TTF) of patients who received at least one month of sunitinib or everolimus in monotherapy.

Results

Thirty-three patients were identified from September 2009 to April 2018. Most were male 60.6%. Median Ki67 was 9%, liver metastases were present in 97%. The majority of tumors were non-functioning. Thirty-one patients received everolimus, of them 8 patients had germline mutations (6 in MEN1 and 2 in VHL genes). Nine patients received sunitinib, of them 3 had germline mutation (2 in MEN1 and 1 in VHL genes). In a median follow up of 26 months, among everolimus-treated patients, mTTF and mPFS were numerically superior in patients with germline mutations compared with those with sporadic pNETs (mTTF: 16.1 vs. 9.9 months, P=0.888; mPFS: 33.1 vs. 12.3 months, P=0.383). The disease control rate with everolimus was numerically higher in favor of germline mutated tumors compared to sporadic ones (87.5% vs. 68.4%). Sunitinib was used by 1 patient with VHL syndrome, achieving a PFS of 17.6 months. In the subgroup of sporadic pNETs, sunitinib was used by 6 patients reaching a mPFS of 18 months (range, 5-25 months), predominantly in second line.

Conclusions

Our study suggests that everolimus may offer a prolonged tumor control in pNETS with germline mutations (MEN1 or VHL) compared to sporadic ones. The small number of patients and the retrospective nature of this study precludes any definitive conclusions.

The Treatment Landscape and New Opportunities of Molecular Targeted Therapies in Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms that originate from neuroendocrine stem cells and express both neural and endocrine markers. They are found in almost every organ, and while NENs are mostly associated with slow growth, complications due to the uncontrolled secretion of active peptides, and metastatic disease, may significantly impair the quality of life and can ultimately lead to the death of affected individuals. Expanding knowledge of the genetic, epigenetic, and proteomic landscapes of NENs has led to a better understanding of their molecular pathology and consequently increased treatment options for patients. Here, we review the principal breakthroughs in NEN treatment management, owing largely to omics technologies over the last few years, current recommendations of systemic treatment, and ongoing research into the identification of predictive and response biomarkers based on molecular targeted therapies.

Neutrophil Lymphocyte Ratio and Transarterial Chemoembolization in Neuroendocrine Tumor Metastases

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) has been shown to be predictive of outcomes in various cancers, including neuroendocrine tumors (NETs), and cancer-related treatments, including transarterial chemoembolization (TACE). We hypothesized that NLR could be predictive of response to TACE in patients with metastatic NET.

METHODS

We reviewed 262 patients who underwent TACE for metastatic NET at a single tertiary medical center from 2000 to 2016. NLR was calculated from blood work drawn 1 d before TACE, as well as 1 d, 1 wk, and 6 mo after treatment.

RESULTS

The median post-TACE overall survival (OS) of the entire cohort was 30.1 mo. Median OS of patients with a pre-TACE NLR ≤ 4 was 33.3 mo versus 21.1 mo for patients with a pre-TACE NLR >4 (P = 0.005). At 6 mo, the median OS for patients with post-TACE NLR > pre-TACE NLR was 21.4 mo versus 25.8 mo for patients with post-TACE NLR ≤ pre-TACE NLR (P = 0.007). On multivariate analysis, both pre-TACE NLR and 6-mo post-TACE NLR were independent predictors of survival. NLR values from 1-d and 1-wk post-TACE did not correlate with outcome.

CONCLUSIONS

An elevated NLR pre-TACE and an NLR that has not returned to its pre-TACE value several months after TACE correlate with outcomes in patients with NET and liver metastases. This value can easily be calculated from laboratory results routinely obtained as part of preprocedural and postprocedural care, potential treatment strategies.

Activation of the ileal neuroendocrine tumor cell line P-STS by acetylcholine is amplified by histamine: role of H3R and H4R

Neuroendocrine tumors may present with pseudoallergic reactions like diarrhea and idiopathic anaphylaxis. Here we present the P-STS human ileal neuroendocrine cell line as a model cell line for these tumors. Neuroendocrine markers and changes in cytoplasmic calcium concentration ([Ca2+]i) in response to several possible activators of 5-hydroxytryptamine (5-HT) release were analyzed. P-STS cells still expressed chromogranin A and synaptophysin after 2 years of culture. Tryptophan hydroxylase 1 mRNA and a low amount of 5-HT were also detected. Acetylcholine (ACh) caused a rise in [Ca2+]i. Somatostatin inhibited, whereas histamine (HA) but not the HA receptor ligand betahistine enhanced activation by ACh. The [Ca2+]i response to ACh/HA was inhibited by the HA receptor H3 (H3R) agonist methimepip and by the antidepressant imipramine. Further [Ca2+]i response studies indicated the presence of H4Rs and of a functional calcium sensing receptor. High or low affinity IgE receptor protein or mRNA were not detected. Taken together, neuroendocrine markers and response to intestinal neurotransmitters approve the P-STS cell line as a valuable model for enterochromaffin cells. Enhancement of their ACh-induced pro-secretory response by HA, with a role for H3R and H4R, suggests an amplifying role of neuroendocrine cells in allergen-induced diarrhea or anaphylaxis.

ACR Appropriateness Criteria Radiologic Management of Hepatic Malignancy

Management of primary and secondary hepatic malignancy is a complex problem. Achieving optimal care for this challenging population often requires the involvement of multiple medical and surgical disciplines. Because of the wide variety of potential therapies, treatment protocols for various malignancies continue to evolve. Consequently, development of appropriate therapeutic algorithms necessitates consideration of medical options, such as systemic chemotherapy; surgical options, such as resection or transplantation; and loco-regional therapies, such as thermal ablation and transarterial embolization techniques. This article provides a review of treatment strategies for the three most common subtypes of hepatic malignancy treated with loco-regional therapies: hepatocellular carcinoma, neuroendocrine metastases, and colorectal metastases. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Selective internal radiation therapy for the treatment of inoperable neuroendocrine tumor liver metastases

Neuroendocrine tumor liver metastases are commonly present at the time of neuroendocrine tumor diagnosis. Surgical resection is potentially curative and achieves the best long-term results but is not feasible in many patients. Angiographic liver-directed treatment modalities such as transarterial embolization, transarterial chemoembolization and selective internal radiotherapy using Yttrium-90 ([90]Y)-labeled microspheres have been shown to be effective treatments with liver predominant disease. Here, we review the management of neuroendocrine tumor liver metastases including selective internal radiotherapy.

Treatment options for advanced pancreatic neuroendocrine tumors: what is on the horizon?

Abstract: 

Treatment options for patients with advanced or metastatic pancreatic tumors (pNET) have expanded greatly in recent years. These treatments include resection, ablation or embolization of liver metastases and systemic therapy with everolimus or sunitinib and cytotoxic agents. New investigational approaches include the use of inhibitors of multiple downstream effectors in the PI3K/Akt/mTOR pathway, novel antiangiogenics, somatostatin analogues, new tyrosine kinase inhibitors and peptide receptor radionuclide therapy. The treatment horizon for pNET patients may offer improved duration of tumor control and survival and more effective symptom control.

Gastroenteropancreatic endocrine tumors

Gastroenteropancreatic endocrine tumors (GEP-NETs) are relatively uncommon; comprising approximately 0.5% of all human cancers. Although they often exhibit relatively indolent clinical courses, GEP-NETs have the potential for lethal progression. Due to their scarcity and various technical challenges, GEP-NETs have been understudied. As a consequence, we have few diagnostic, prognostic and predictive biomarkers for these tumors. Early detection and surgical removal is currently the only reliable curative treatment for GEP-NET patients; many of whom, unfortunately, present with advanced disease. Here, we review the genetics and epigenetics of GEP-NETs. The last few years have witnessed unprecedented technological advances in these fields, and their application to GEP-NETS has already led to important new information on the molecular abnormalities underlying them. As outlined here, we expect that "omics" studies will provide us with new diagnostic and prognostic biomarkers, inform the development of improved pre-clinical models, and identify novel therapeutic targets for GEP-NET patients.

ACR Appropriateness Criteria radiologic management of hepatic malignancy

Management of hepatic malignancy is a challenging clinical problem involving several different medical and surgical disciplines. Because of the wide variety of potential therapies, treatment protocols for various malignancies continue to evolve. Consequently, development of appropriate therapeutic algorithms necessitates consideration of medical options, such as systemic chemotherapy; surgical options, such as resection or transplantation; and locoregional therapies, such as thermal ablation and transarterial embolization. The authors discuss treatment strategies for the 3 most common subtypes of hepatic malignancy treated with locoregional therapies: hepatocellular carcinoma, neuroendocrine metastases, and colorectal metastases. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

The Treatment of Liver Metastases in Patients with Neuroendocrine Tumors in 2012

Neuroendocrine tumors (NETs) comprise a heterogeneous group of tumors that form a distinct entity. Approximately 75-80% of patients present with liver metastases at the time of their diagnosis, and 20%-25% will develop these lesions in the course of their disease. The presence of secondary deposits in the liver significantly increases the morbidity and mortality in these patients. The only potentially curative treatment is the surgical resection of the primary tumor and hepatic lesions. However, only 10% of patients presents under ideal conditions for that approach. Several techniques aimed at localized liver lesions have been applied also with interesting results in terms of survival and symptom control. The same has been demonstrated with new systemic therapies (target therapies). However, these are still under study, in order to define their true role in the management of these patients. This paper intends to address, in a general way, the various treatment options in patients with liver metastases from neuroendocrine tumors.

Treatment of liver metastases in patients with digestive neuroendocrine tumors

BACKGROUND

Liver metastases are a strong prognostic indicator in patients with gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs). Therapeutic options for metastatic NETs are expanding and not mutually exclusive.

AIMS

This paper reviews the literature relating to multidisciplinary approach towards GEP-NET metastases, to highlight advances in knowledge regarding these tumors, and to understand the interdisciplinary management of individual patients.

METHODS

A PubMed search was performed for English-language publications from 1995 through 2012. Reference lists from studies selected were manually searched to identify further relevant reports. Manuscripts comparing different therapeutic options and advances for GEP-NET-related liver metastases were selected.

RESULTS

There is considerable controversy regarding the optimal management of GEP-NET metastases. Although radical surgery still remains the gold standard, a variety of other therapeutic options are available for metastatic GEP-NETs, including loco-regional chemotherapy/radiotherapy, radioembolization, systemic peptide receptor radionuclide therapy, biotherapy, and chemotherapy. In selected patients, liver transplantation should also be considered. Systemic somatostatin analogues and/or interferon show anti-proliferative effects, representing an appropriate first-line treatment for most patients. In advanced metastatic NETs, recent options include targeted therapies (i.e., everolimus and sunitinib).

CONCLUSIONS

It is evident that multidisciplinary care and multimodality treatments remain the cornerstone of management of NET patients. Since NETs often show a more indolent behavior compared to other malignancies, physicians should aim to preserve a satisfactory quality of life for the patient by personalizing the therapeutic approach according to the tumor's features and prognostic factors.

Treatment options for unresectable neuroendocrine liver metastases

Hepatic metastases develop in 85% of patients with gastroenteropancreatic neuroendocrine tumors. Radical surgery, which involves resection of the primary and liver metastases, is the mainstay of treatment, with 60-70% 5-year survival and 35% 10-year survival rates. However, less than 15% of neuroendocrine tumor liver metastases (NETLMs) are resectable, owing either to multifocality or the inability to preserve sufficient parenchyma following resection. This article deals with the therapeutic modalities available for nonresectable liver metastases, and the therapeutic options available for management of nonresectable NETLMs are discussed. Targeted therapies for NETLMs include hepatic artery embolization, transcatheter arterial chemoembolization, radiolabeled/drug-eluting microspheres, radiofrequency ablation, cryoablation and phenol injection. Hepatic artery embolization/transcatheter arterial chemoembolization is associated with 75-100% symptom relief and an objective tumor response varying from 33 to 80%. Other modalities, such as biotherapy, peptide receptor therapy and chemotherapy, target both the primary and metastatic disease. Their effects on NETLMs as a subgroup have not been evaluated. Various therapeutic options are available for the treatment of unresectable NETLMs. Most offer significant symptomatic relief, with only a few comparative studies showing survival benefit. Most of the available evidence is based on retrospective and prospective case series rather than randomized controlled trials. Well-designed studies on existing treatment modalities and the search for newer therapeutic options are required.

Treatment of liver metastases in patients with neuroendocrine tumors: a comprehensive review

Patients diagnosed with Neuroendocrine Tumors (NET) often are also diagnosed with Neuroendocrine Liver Metastases (NLM) during the course of their disease. NLM can cause significant morbidity and mortality, oftentimes much more than compared to patients with NET. Treatment options have been limited in the past, focusing on surgical resections, for which only a minority of patients are candidates. However, developments of new treatment modalities have progressed rapidly and patients with NLM now have significantly more options, including surgical-directed therapies; liver-directed therapies; and nonsurgical, non-liver-directed therapies. This review provides information about the roles of hepatic resection, orthotopic liver resection, radiofrequency ablation, hepatic artery embolization and hepatic artery chemoembolization, hepatic artery radioembolization and selective internal radiation therapy, peptide receptor radionuclide therapy, systemic chemotherapy, biotherapies including somatostatin analogs and interferon-α, vascular endothelial growth factor and mTOR targets, and microRNA-regulated pathways. Given these new options, the clinician can tailor therapy specific to the patient diagnosed with NLM, thereby giving the patient the best possible chance of prolonged survival.