Impact of Previous Somatostatin Analogue Use on the Activity of Everolimus in Patients with Advanced Neuroendocrine Tumors: Analysis from the Phase III RADIANT-2 Trial

Novel preclinical gastroenteropancreatic neuroendocrine neoplasia models demonstrate the feasibility of mutation-based targeted therapy

PURPOSE

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) form a rare and remarkably heterogeneous group of tumors. Therefore, establishing personalized therapies is eminently challenging. To achieve progress in preclinical drug development, there is an urgent need for relevant tumor models.

METHODS

We successfully established three gastroenteropancreatic neuroendocrine tumor (GEP-NET) cell lines (NT-18P, NT-18LM, NT-36) and two gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) cell lines (NT-32 and NT-38). We performed a comprehensive characterization of morphology, NET differentiation, proliferation and intracellular signaling pathways of these five cell lines and, in addition, of the NT-3 GEP-NET cell line. Additionally, we conducted panel sequencing to identify genomic alterations suitable for mutation-based targeted therapy.

RESULTS

We found that the GEP-NEN cell lines exhibit a stable neuroendocrine phenotype. Functional kinome profiling revealed a higher activity of serine/threonine kinases (STK) as well as protein tyrosine kinases (PTK) in the GEP-NET cell lines NT-3 and NT-18LM compared to the GEP-NEC cell lines NT-32 and NT-38. Panel sequencing revealed a mutation in Death Domain Associated Protein (DAXX), sensitizing NT-18LM to the Ataxia telangiectasia and Rad3 related (ATR) inhibitor Berzosertib, and a mutation in AT-Rich Interaction Domain 1A (ARID1A), sensitizing NT-38 to the Aurora kinase A inhibitor Alisertib. Small interfering RNA-mediated knock down of DAXX in the DAXX wild type cell line NT-3 sensitized these cells to Berzosertib.

CONCLUSIONS

The newly established GEP-NET and GEP-NEC cell lines represent comprehensive preclinical in vitro models suitable to decipher GEP-NEN biology and pathogenesis. Additionally, we present the first results of a GEP-NEN-specific mutation-based targeted therapy. These findings open up new potentialities for personalized therapies in GEP-NEN.

Efficacy and Safety of First-Line Everolimus Therapy Alone or in Combination with Octreotide in Gastroenteropancreatic Neuroendocrine Tumors. A Hellenic Cooperative Oncology Group (HeCOG) Study

The purpose of this study was to explore the efficacy and safety of everolimus administered as a first-line treatment in newly diagnosed patients with metastatic or inoperable gastroenteropancreatic neuroendocrine tumors (GEP NETs). This phase II, multicenter, single-arm study included patients with well-differentiated GEP NETs and a Ki67 < 20%. Everolimus, at 10 mg/day, was administered until disease progression; 18 patients (72%) concomitantly received octreotide long-acting release (LAR), at 30 mg/month. The primary endpoint was the 15-month progression-free survival (PFS) rate. Twenty-five patients (grade 1: 11 patients, grade 2: 14 patients) were enrolled between August 2012 and October 2015. At a median follow-up of 58.1 months, the median PFS was 14.6 months, while the 15-month PFS rate was 48%; median overall survival had not been reached yet. Normal baseline chromogranin A (<4 nmol/l) confirmed a longer PFS (HR = 0.25, 95% CI 0.08–0.77, p = 0.016). Seven patients (28%) achieved an objective response (one complete response and six partial responses) in a median of 2.6 months. Twenty-three grade 3–4 events were recorded (14 patients). No fatal reactions occurred. This prospective phase II study unravels the notable activity of everolimus as a first-line treatment in patients with GEP NETS and contributes valuable information about the high activity of the combination of everolimus and octreotide LAR in this setting. Clinical trial information: NCT01648465.

Management of Gastrointestinal Neuroendocrine Tumors

Neuroendocrine neoplasms (NENs) are derived from neuroendocrine cell system and can have benign or malignant characteristics. They are rare tumors, but have been increasing in incidence over the past 40 years. Patients with NENs may develop symptoms due to primary tumor invasion, metastasis, or from secretion of hormonally active tumor substances. Multiple imaging modalities are used for diagnosis and staging, including specialty scans such as ¹¹¹In pentetreotide (Octreoscan) and ⁶⁸Gallium-DOTATATE, along with endoscopy, endoscopic ultrasound, and biochemical marker testing. Treatment involves both surgical approach, for both primary and metastatic lesions, as well as medical management for symptom management and disease progression. This article will review the current clinical knowledge regarding the diagnosis, treatment, and prognosis of these fascinating neoplasms and the associated hormonal syndromes.

Targeted Systemic Treatment of Neuroendocrine Tumors: Current Options and Future Perspectives

Neuroendocrine tumors (NETs) originate from the neuroendocrine cell system in the bronchial and gastrointestinal tract and can produce hormones leading to distinct clinical syndromes. Systemic treatment of patients with unresectable NETs aims to control symptoms related to hormonal overproduction and tumor growth. In the last decades prognosis has improved as a result of increased detection of early stage disease and the introduction of somatostatin analogs (SSAs) as well as several new therapeutic options. SSAs are the first-line medical treatment of NETs and can control hormonal production and tumor growth. The development of next-generation multireceptor targeted and radiolabelled somatostatin analogs, as well as target-directed therapies (as second-line treatment options) further improve progression-free survival in NET patients. To date, however, a significant prolongation of overall survival with systemic treatment in NET has not been convincingly demonstrated. Several new medical options and treatment combinations will become available in the upcoming years, and although preliminary results of preclinical and clinical trials are encouraging, large, preferrably randomized clinical studies are required to provide definitive evidence of their effect on survival and symptom control.

Interaction between somatostatin analogues and targeted therapies in neuroendocrine tumor cells

Somatostatin analogues (SSA) represent the standard of care for symptom control in patients with functional gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). In addition, SSA exert significant anti-proliferative effects in mid-gut and pancreatic NET (PanNET). In parallel, molecularly targeted therapies (MTT) have been shown to improve progression free survival (PFS) in patients with PanNET. However, due to either primary or acquired resistance to MTT, their impact on overall survival (OS) remains unclear. To date, various hypotheses exist to explain differences in patient responsiveness to SSA and MTT. However, data addressing one of the most pivotal questions, whether combining SSA with novel MTT will result in synergistic or additive efficacy compared to monotherapy, are lacking. The aim of this study is to characterize the interaction, optimal sequence and dosing of SSA-based and molecularly targeted therapies in PanNET. Somatostatin receptor subtypes 1–5 (SSTR) were evaluated in the neuroendocrine cell lines Bon1, QGP1 and Ins-1 via immunoblot and qRT-PCR. The impact of the SSA-analogue lanreotide alone or in combination with the MTT sunitinib, everolimus and regorafenib on intracellular signalling, hormone secretion and cell proliferation was determined in cell lysates and supernatants. In addition, synergistic effects of SSA and MTT in various sequential therapeutic approaches were investigated. SSTR were differently expressed in the examined neuroendocrine tumor cell lines. SSTR modulation via lanreotide moderately influenced proliferation, mainly via modulating AKT and ERK signalling, which was paralleled by decreased chromogranin A (CgA) expression and secretion. Interestingly, MTT treatment with regorafenib upregulated the expression of SSTR-2 and -5, while sunitinib and everolimus did not significantly alter SSTR expression. Cell viability was significantly reduced by all MTT, with regorafenib exerting the most significant effects. However, compared to the marked effects of MTT alone, synergistic effects of combined MTT and lanreotide treatment were only modest and time- and dose-dependent. SSTR are differentially expressed in various NEN cell lines. Their expression is influenced by MTT treatment. Various sequential or simultaneous combinations of lanreotide and MTT did not lead to significant synergistic effects.

Treatments for patients with advanced neuroendocrine tumors: a network meta-analysis

Background

It remains unknown which is the most effective regimen among the available therapies for advanced well-differentiated neuroendocrine tumors (NETs). We performed a network meta-analysis to address this important issue.

Methods

PubMed, Embase, Web of Science, Cochrane Library, and major international scientific meetings were searched for relevant randomized controlled trials (RCTs). Progression-free survival (PFS) data was the primary outcome of interest, and overall survival (OS) and serious adverse events (SAEs) were the secondary outcomes of interests, reported as hazard ratio (HR), or odds ratio (OR) and 95% confidence intervals (CIs).

Results

Included in the meta-analysis were 21 eligible articles reporting 15 RCTs with a total of 2922 patients randomized to receive 11 treatments. Peptide receptor radionuclide therapy (PRRT) showed significant PFS advantage over somatostatin analogs (SSA) (HR = 0.21, 95% CI: 0.11-0.41), everolimus (HR = 0.25, 95% CI: 0.11-0.53), sunitinib (HR = 0.29, 95% CI: 0.10-0.82), everolimus+SSA (HR = 0.26, 95% CI: 0.12-0.54), and everolimus+bevacizumab (HR = 0.31, 95% CI: 0.11-0.82). OS findings were not significantly different between treatments. In terms of treatment rankings of PFS, PRRT had the highest probability (96%) of being the most effective treatment, followed by SSA+bevacizumab (86%) and SSA+interferon-α (IFN-α) (78%). As for toxicity, risk of SAEs was similar between the three treatments. Based on the benefit-risk ratio, PRRT, SSA+bevacizumab, and SSA+IFN-α seemed to be the best, second-, and third-best treatment, respectively.

Conclusions

PRRT is likely to be the most preferable treatment for patients with advanced well-differentiated NETs. SSA+bevacizumab and SSA+IFN-α also seem to be more effective regimens with limited risk of SAEs.

Effect of Lanreotide Depot/Autogel on Urinary 5-Hydroxyindoleacetic Acid and Plasma Chromogranin A Biomarkers in Nonfunctional Metastatic Enteropancreatic Neuroendocrine Tumors

BACKGROUND

Urinary 5-hydroxyindoleacetic acid (5-HIAA) is an established biomarker in neuroendocrine tumors and carcinoid syndrome; however, its role in nonfunctional neuroendocrine tumors is not defined. We present post hoc data on urinary 5-HIAA and plasma chromogranin A (CgA) from the CLARINET study.

METHODS

Patients with well- or moderately differentiated, nonfunctioning, locally advanced or metastatic enteropancreatic neuroendocrine tumors were randomized to deep subcutaneous lanreotide depot/autogel 120 mg or placebo once every 28 days for 96 weeks. Tumor response, evaluated centrally (RECIST 1.0), and progression-free survival (PFS) were assessed by treatment and biochemical response, defined as (a) baseline >upper limit of normal (ULN, 41.6 μmol per day 5-HIAA; 98.1 μg/L CgA) and (b) ≥50% decrease from baseline and to ≤ULN value on study.

RESULTS

Forty-eight percent (82 of 171; lanreotide, n = 45; placebo, n = 37) and 66% (129 of 195; lanreotide, n = 65; placebo, n = 64) of randomized patients had 5-HIAA and CgA > ULN at baseline. Among patients with >ULN baseline values who did not progress after 96 weeks of treatment, significantly greater reductions in 5-HIAA and CgA were observed in lanreotide-treated versus placebo-treated patients throughout the study (all p < .05). PFS was significantly prolonged among 5-HIAA responders versus nonresponders (median not reached vs. 16.2 months, p < .0001; hazard ratio [HR] = 0.21, 95% confidence interval [CI], 0.09-0.48) and CgA responders versus nonresponders (median not reached vs. 16.2 months, p = .0070; HR = 0.30, 95% CI, 0.12-0.76), regardless of treatment arm. PFS was also significantly prolonged among lanreotide-treated 5-HIAA responders versus nonresponders (p = .0071) but was not significantly different among placebo-treated 5-HIAA responders versus nonresponders. There were no significant differences in PFS between lanreotide-treated CgA responders versus nonresponders or between placebo-treated CgA responders versus nonresponders.

CONCLUSIONS

The 5-HIAA findings are noteworthy because they occurred in patients with nonfunctioning enteropancreatic neuroendocrine tumors. Monitoring 5-HIAA and CgA may be useful when treating patients with nonfunctional neuroendocrine tumors.

IMPLICATIONS FOR PRACTICE

Current guidelines focus only on the monitoring of 5-hydroxyindoleacetic acid (5-HIAA) in the diagnosis and management of functional neuroendocrine tumors with carcinoid syndrome. The current post hoc analysis of patients with nonfunctional enteropancreatic neuroendocrine tumors in the CLARINET study demonstrated that measuring and following both 5-HIAA and chromogranin A as biomarkers of disease progression may be useful in the management of patients with nonfunctional neuroendocrine tumors.

BIOCHEMICAL RESPONSES IN SYMPTOMATIC AND ASYMPTOMATIC PATIENTS WITH NEUROENDOCRINE TUMORS: POOLED ANALYSIS OF 2 PHASE 3 TRIALS

OBJECTIVE

Neuroendocrine tumors (NETs) are associated with elevated 5-hydroxyindoleacetic acid (5-HIAA) and chromogranin A (CgA) levels. This study aimed to analyze relationships between urinary 5-HIAA and plasma CgA levels and clinical outcomes.

METHODS

Centrally assessed biomarker levels and correlations with progression-free survival (PFS) and carcinoid syndrome (CS) symptom control were evaluated in a pooled analysis of CLARINET (96-week randomized, double-blind, placebo-controlled) and ELECT (16-week randomized, double-blind, placebo-controlled, 32-week initial open label and ≥2 year long-term extension open label) studies of adults with NETs, with (ELECT) or without (CLARINET) CS at 97 institutions. Patients were treated with subcutaneous lanreotide depot 120 mg monthly.

RESULTS

Of 319 pooled patients, 86% and 95% had baseline 5-HIAA and CgA data, respectively, with 47% and 74% having levels greater than the upper limit of normal (ULN). PFS was longer among patients who experienced a decrease in biomarker levels at week 12, with statistical significance reached in the CgA cohort (not reached vs. 14.4 months; P<.0001). A large proportion (87%) of patients without symptoms of CS in the CLARINET study had detectable levels of 5-HIAA (48% >ULN). In ELECT, patients with CS who received lanreotide and experienced a biochemical response (≥50% decrease from baseline) achieved greater symptom control.

CONCLUSION

This pooled analysis of two randomized, placebo-controlled trials demonstrated that 5-HIAA and CgA are secreted as biochemical biomarkers in many patients with NETs, regardless of clinical syndromes. Significant biochemical response was associated with improved clinical outcomes, as measured by improved PFS or improved CS symptom control.

ABBREVIATIONS

5-HIAA = 5-hydroxyindoleacetic acid; CgA = chromogranin A; CI = confidence interval; CLARINET = Controlled Study of Lanreotide Antiproliferative Response in Neuroendocrine Tumors; CS = carcinoid syndrome; ELECT = Evaluation of Lanreotide Depot/Autogel Efficacy and Safety as a Carcinoid Syndrome Treatment; HR = hazard ratio; ITT = intention-to-treat; NET = neuroendocrine tumor; PanNET = pancreatic NET; PFS = progression-free survival; PPI = proton pump inhibitor; SSA = somatostatin analogue; ULN = upper limit of normal.

Systematic literature review of the antitumor effect of octreotide in neuroendocrine tumors

AIM

To provide a comprehensive examination of the existing evidence of the antitumor effect of long-acting octreotide in neuroendocrine tumors (NETs).

METHODS

A systematic literature review of clinical trials and observational studies was conducted in PubMed, EMBASE, and Cochrane through January 18, 2017. Conference abstracts for 2015 and 2016 from 5 scientific meetings were also searched.

RESULTS

Of 41 articles/abstracts identified, 13 unique studies compared octreotide with active or no treatment. Two of the 13 studies were clinical trials; the remaining were observational studies. The phase 3 Placebo-Controlled, Double-Blind, Prospective, Randomized Study of the Effect of Octreotide long-acting repeatable (LAR) in the Control of Tumor Growth in Patients with Metastatic Neuroendocrine Midgut Tumors clinical trial showed that long-acting octreotide significantly prolonged time to tumor progression compared with placebo in patients with functionally active and inactive metastatic midgut NETs; no statistically significant difference in overall survival (OS) was observed, possibly due to the crossover of placebo patients to octreotide. Retrospective observational studies found that long-acting octreotide use was associated with significantly longer OS than no octreotide use for patients with distant metastases although not for those with local/regional disease.

CONCLUSION

The clinical trial and observational studies with informative evidence support long-acting octreotide’s antitumor effect on time to tumor progression and OS. This review showed the rarity of existing studies assessing octreotide’s antitumor effect and recommends that future research is warranted.

Everolimus in the treatment of neuroendocrine tumors: efficacy, side-effects, resistance, and factors affecting its place in the treatment sequence

INTRODUCTION

Since the initial approval of everolimus in 2011, there have been a number of important changes in therapeutic/diagnostic modalities as well as classification/staging systems of neuroendocrine tumors (NETs), which can significantly impact the use of everolimus in patients with advanced NETs. Areas covered: The efficacy of everolimus monotherapy and combination therapy demonstrated in clinical studies involving patients with advanced NETs are reviewed. Several factors affecting everolimus use are described including: the development and routine use of NET classification/staging systems; widespread use of molecular imaging modalities; side effects; drug resistance; and the availability of other treatment options. Furthermore, the current position of everolimus in the treatment approach is discussed, taking into account the recommendations from the recent guidelines. Expert opinion: Although everolimus demonstrated its high efficacy and tolerability in the RADIANT trials and other clinical studies, there still remain a number of controversies related to everolimus treatment in the management of NETs. The synergistic anti-growth effect of other agents in combination with everolimus or its effect on overall survival have not been established. The appropriate order of the use of everolimus in the treatment of advanced NETs still remains unclear, which needs to be defined in further studies and will be addressed in the new guidelines.

Treatment Patterns and Clinical Outcomes in Patients With Metastatic Gastroenteropancreatic Neuroendocrine Tumors Treated in the Community Practice Setting in the United States

OBJECTIVE

This study was conducted to understand treatment patterns and clinical outcomes in metastatic gastroenteropancreatic neuroendocrine tumor patients treated in a large community oncology network.

METHODS

This retrospective study used the McKesson Specialty Health/US Oncology Network iKnowMed electronic health record database with supplemental chart review. Eligibility criteria included a metastatic neuroendocrine tumor diagnosis between January 1, 2008, and to December 31, 2012; at least 2 US Oncology Network visits; and age at least 18 years. Follow-up was through October 31, 2014.

RESULTS

Among the 229 patients identified, median age was 64.0 years, 52.4% were male, 69.4% were white, and 62.9% were overweight/obese. Primary tumor sites included small bowel (47.6%), pancreas (31.4%), and stomach/colorectum (21.0%). There were 16.2% under observation without treatment, 52.4% received only somatostatin analogs (SSAs), and 31.4% received chemotherapy/targeted therapy during treatment. In the first-line setting (n = 192), 77% received SSAs, 12% received chemotherapy, and 10.9% received targeted therapy. Fifty percent of patients receiving octreotide had a relative dose intensity of less than 85%, and 16.7% received above-label dose. Toxicities of SSAs included diarrhea (18.2%), abdominal pain (16.9%), and fatigue (13.5%). Median overall survival from diagnosis was 68.0 months (95% confidence interval, 57.1 to not reached).

CONCLUSIONS

Most metastatic gastroenteropancreatic neuroendocrine tumor patients received systemic treatment with SSAs. Patient treatment used an individualized dosing approach. Overall survival and toxicity were consistent with the published literature.

How do the results of the RADIANT trials impact on the management of NET patients? A systematic review of published studies

In the last five years, everolimus has demonstrated efficacy in the treatment of neuroendocrine tumors (NETs) of different origins; its efficacy and safety were explored in the RADIANT trials, the last of which (RADIANT-4) has been recently published (December 2015). Overall, evidence collected from the RADIANT studies holds promise to change clinical practice for the treatment of NETs.In this paper, we comment on the role of everolimus within the therapeutic algorithm for NETs treatment, based on the systematic analysis of the RADIANT trials and our experience.

A case of long-survival insulinoma with multiple neuroendocline tumour type 1 controlled by multimodal therapy

Insulinomas with multiple neuroendocrine tumour type 1 (MEN1) sometimes have metachronous or recurrent tumours. However, the treatment for these tumours is controversial, and published reports regarding multimodal therapy for insulinomas are limited. We report a 73-year-old woman with recurrent insulinoma with MEN1 successfully controlled by multimodal therapy. She had several complications, and poor performance status. Her hypoglycaemia did not improve after 6-month octreotide LAR; as such, she underwent enucleation of the pancreatic tumour. Within 7 years after the first operation, she underwent four succeeding surgeries for recurrent tumours. Her medications during follow-up were octreotide-LAR and Everolimus. Insulinoma can be managed through various treatment options. Medical treatment includes octreotide-LAR and Everolimus, while surgical approach includes enucleation and pancreaticoduodenectomy. Some tumours, particularly those that are MEN1, can recur repeatedly. Thus, several treatments are needed to control them. We highlight the importance of multimodal therapy, including repeated surgery, for the control of the disease.

Patient-Reported Symptom Control of Diarrhea and Flushing in Patients with Neuroendocrine Tumors Treated with Lanreotide Depot/Autogel: Results from a Randomized, Placebo-Controlled, Double-Blind and 32-Week Open-Label Study

BACKGROUND

In the double-blind (DB) ELECT study, lanreotide depot/autogel significantly reduced versus placebo the need for short-acting octreotide for symptomatic carcinoid syndrome (CS) control in neuroendocrine tumor (NET) patients. Here we present patient-reported symptom data during DB and initial open-label (IOL) treatment.

MATERIALS AND METHODS

Adults with NETs and CS history, with/without prior somatostatin analog use, were randomized to 16 weeks' DB lanreotide 120 mg subcutaneous or placebo every 4 weeks, followed by 32 weeks' IOL lanreotide. Patients recorded diarrhea and/or flushing frequency and severity daily by Interactive Voice (Web) Response System for 1 month prior to randomization and throughout the study.

RESULTS

Of 115 patients randomized (n = 59 lanreotide, n = 56 placebo), 56 lanreotide and 45 placebo patients enrolled in the IOL phase. During DB treatment, least square (LS) mean percentages of days with moderate/severe diarrhea and/or flushing were significantly lower for lanreotide (23.4%) versus placebo (35.8%; LS mean difference [95% confidence interval]: -12.4 [-20.73 to -4.07]; p = .004). For DB lanreotide patients, average daily composite (frequency × severity) diarrhea scores improved significantly between DB and IOL treatment (mean difference: -0.71 [-1.20 to -0.22]; p = .005), and remained stable for diarrhea and/or flushing. For DB placebo patients, composite scores for diarrhea, flushing, and diarrhea and/or flushing improved significantly between DB and IOL treatment (mean differences: -1.07 [-1.65 to -0.49]; -1.06 [-1.93 to -0.19]; and -2.13 [-3.35 to -0.91]; all p ≤ .018).

CONCLUSION

Improved diarrhea and flushing control in CS patients during 16-week lanreotide treatment was sustained during maintenance of lanreotide treatment for the 32-week IOL phase (48 weeks total).

IMPLICATIONS FOR PRACTICE

This study prospectively collected daily patient-reported data on diarrhea and flushing from the ELECT trial to evaluate the direct impact of lanreotide depot on patients' relief of carcinoid syndrome symptoms. Treatment with lanreotide depot was associated with significant reductions in the percentages of days patients reported symptoms of diarrhea and flushing, as well as reductions in the frequency and severity of daily symptoms compared with placebo during 16 weeks of double-blind treatment. These improvements were sustained for 32 additional weeks of open-label lanreotide treatment (i.e., through week 48 of treatment), resulting in clinically meaningful, long-term symptom reduction.

Unravelling the pharmacologic opportunities and future directions for targeted therapies in gastro-intestinal cancers part 2: Neuroendocrine tumours, hepatocellular carcinoma, and gastro-intestinal stromal tumours

Until the 1990s, cytotoxic chemotherapy has been the cornerstone of medical therapy for gastrointestinal (GI) cancers. Better understanding of the cancer cell molecular biology has led to the therapeutic revolution of targeted therapies, i.e. monoclonal antibodies or small molecule inhibitors directed against proteins that are specifically overexpressed or mutated in cancer cells. These agents, being more specific to cancer cells, were expected to be less toxic than conventional cytotoxic agents. However, their effects have sometimes been disappointing, due to intrinsic or acquired resistance mechanisms, or to an activity restricted to some tumour settings, illustrating the importance of patient selection and early identification of predictive biomarkers of response to these therapies. Targeted agents have provided clinical benefit in many GI cancer types. Particularly, some GI tumours are considered chemoresistant and targeted therapies have offered a new therapeutic base for their management. Hence, somatostatin receptor-directed strategies, sorafenib, and imatinib have revolutioned the management of neuroendocrine tumours (NET), hepatocellular carcinoma (HCC), and gastrointestinal stromal tumours (GIST), respectively, and are now used as first-line treatment in many patients affected by these tumours. However, these agents face problems of resistances and identification of predictive biomarkers from imaging and/or biology. We propose a comprehensive two-part review providing a panoramic approach of the successes and failures of targeted agents in GI cancers to unravel the pharmacologic opportunities and future directions for these agents in GI oncology. In this second part, we will focus on NET, HCC, and GIST, whose treatment relies primarily on targeted therapies.

Emerging use of everolimus in the treatment of neuroendocrine tumors

Neuroendocrine tumors (NETs) consist of a diverse family of malignancies, which are derived from neuroendocrine cells, most commonly originating from the gastroenteropancreatic (GEP) tract or the bronchopulmonary system. In general, NETs are more indolent than epithelial tumors, with median survival rates of longer than 30 months. The upregulation of mTOR pathway has been shown to play a pivotal role in NET pathogenesis. Inhibition of mTOR protein with everolimus represents a progress in the treatment of advanced NETs. Everolimus has shown a significant improvement in progression-free survival (PFS) among patients with pancreatic NETs (pNETs) and nonfunctional GEP and lung NETs in the Phase III RAD001 in Advanced Neuroendocrine Tumors (RADIANT)-3 and RADIANT-4 studies, respectively. In addition, the combination of everolimus with octreotide showed a clinically significant improvement versus octreotide alone in functional NETs in the RADIANT-2 trial. These studies led to the US Food and Drug Administration (FDA) and European Medical Agency (EMA) approval of everolimus. Safety profile of everolimus is generally acceptable. The most common adverse events are stomatitis, diarrhea, rash and fatigue. There is a growing range of novel treatment options in the setting of NETs, but there are no data comparing the activity of different treatment strategies. Thus, treatment decisions are based on different aspects, such as clinical course, patient symptomatology, primary tumor site, tumor functionality, rate of progression and burden of disease. Further research is required to clarify the treatment sequencing to achieve the maximum prolongation in survival and maintenance of quality of life. Future research should concentrate on identification of predictive biomarkers for benefit from different therapies, and studies should also include quality of life as an important measurement in this disease.

Management of the hormonal syndrome of neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors (GEP/NET) are unusual and rare neoplasms that present many clinical challenges. They characteristically synthesize store and secrete a variety of peptides and neuroamines which can lead to the development of distinct clinical syndrome, however many are clinically silent until late presentation with mass effects. Management strategies include surgery cure and cytoreduction with the use of somatostatin analogues. Somatostatin have a broad range of biological actions that include inhibition of exocrine and endocrine secretions, gut motility, cell proliferation, cell survival and angiogenesis. Five somatostatin receptors (SSTR1-SSTR5) have been cloned and characterized. Somatostatin analogues include octreotide and lanreotide are effective medical tools in the treatment and present selectivity for SSTR2 and SSTR5. During treatment is seen disapperance of flushing, normalization of bowel movements and reduction of serotonin and 5-hydroxyindole acetic acid (5-HIAA) secretion. Telotristat represents a novel approach by specifically inhibiting serotonin synthesis and as such, is a promising potential new treatment for patients with carcinoid syndrome. To pancreatic functionig neuroendocrine tumors belongs insulinoma, gastrinoma, glucagonoma and VIP-oma. Medical management in patients with insulinoma include diazoxide which suppresses insulin release. Also mTOR inhibitors may inhibit insulin secretion. Treatment of gastrinoma include both proton pump inhibitors (PPIs) and histamine H2 - receptor antagonists. In patients with glucagonomas hyperglycaemia can be controlled using insulin and oral blood glucose lowering drugs. In malignant glucagonomas smatostatin analogues are effective in controlling necrolytic migratory erythemia. Severe cases of the VIP-oma syndrome require supplementation of fluid losses. Octreotide reduce tumoral VIP secretion and control secretory diarrhoea.

Gastroenteropancreatic neuroendocrine tumors: recommendations of Turkish multidisciplinary neuroendocrine tumor study group on diagnosis, treatment and follow-up

Gastroenteropancreatic neuroendocrine tumors (GEPNETs) are a relatively rare, heterogeneous group of diseases in which important advances have been observed in the diagnosis and treatment as well as in our understanding of the biology and genetics of the disease in recent years. Given the insufficient scientific data available on evidence-based management of GEPNETs and the differences in circumstances in individual countries, a multidisciplinary study group was established to provide guidelines for the management of GEPNETS. This study group consisted of a medical oncologist, endocrinologist, surgeon, pathologist, gastroenterologist, and a nuclear medicine specialist, who aimed to prepare a practical guide in the light of existing scientific data and international guidelines, to be used in common clinical practice.

Everolimus treatment for neuroendocrine tumors: latest results and clinical potential

Neuroendocrine tumors (NETs) are a heterogeneous class of diseases characterized by challenging management. Preclinical evidence shows that the PI3K/AKT/mTOR signaling pathway plays a central role in the pathogenesis and progression of NETs. Everolimus is a direct inhibitor of this pathway, and therefore this molecule appears to be a well-grounded strategy for the treatment of NETs, capable of changing clinical practice. The efficacy and safety of everolimus was demonstrated in the RADIANT trials. In this work, we comment on the results of the RADIANT trials, and other recent key evidence from fully published clinical trials on everolimus, and we discuss the current role of everolimus in the treatment of NETs.

Management of controversial gastroenteropancreatic neuroendocrine tumour clinical situations with somatostatin analogues: results of a Delphi questionnaire panel from the NETPraxis program

BACKGROUND

There are clinical situations (CS) in which the use of somatostatin analogs (SSAs) in patients with neuroendocrine tumors (NET) is controversial due to lack of evidence. A Delphi study was conducted to develop common treatment guidelines for these CS, based on clinical practice and expert opinion of Spanish oncologists.

METHODS

A scientific committee identified 5 CS with a common core (c-c) [non-functioning NET, not susceptible of surgery/locoregional therapy, Ki67 < 10 % (except for CS5: >10 %), ECOG ≤ 2], and controversy regarding use of SSAs, and prepared a Delphi questionnaire of 48 treatment statements. Statements were rated on a 1 (completely disagree) to 9 (completely agree) scale. Responses were grouped by tertiles: 1-3: Disagreement, 4-6: Neutral, 7-9: Agreement. Consensus was reached when the responses of ≥2/3 participants were located in the same tertile as the median value of all reported responses for that statement.

RESULTS

Sixty five (81.2 %) of 80 invited oncologists with experience in the management of NETs answered a first round of the questionnaire and 57 (87.7 %) of those 65 answered a second round (mean age 43.5 years; 53.8 % women; median time of experience 9 years). Consensus was obtained in 42 (36 agreement and 6 disagreement) of the 48 statements (87.5 %). Regarding CS1 (Enteropancreatic NET, c-c, non-progressive in the last 3-6 months), overall, SSA treatment is recommended (a wait and see approach is anecdotal and reserved for fragile patients or with low tumor load or ki-67 < 2 %); CS2 (Pancreatic NET, c-c), overall, SSA monotherapy is recommended, except when high tumor load or tumor progression exists, where combination therapy would be considered; CS3 [Gastroenteropancreatic (GEP)-NET, c-c, in treatment with anti-proliferative dose of SSA and progressing], overall, SSA maintenance is recommended at the time of progression, with or without adding molecular targeted drugs; CS4 (GEP-NET, c-c, and negative octreoscan®), SSA in monotherapy is only considered in low-risk patients (low tumor load and Ki-67 < 5 %); CS5 [GEP-NET, c-c (ki67 > 10 %), and positive octreoscan®], monotherapy with SSA is mainly considered in patients with comorbidities.

CONCLUSION

Several recommendations regarding use of SSAs in controversial NET CS were reached in consensus and might be considered as treatment guideline.

Everolimus in the treatment of neuroendocrine tumors of the respiratory and gastroenteropancreatic systems

Neuroendocrine tumors (NETs) are a rare diverse group of malignancies occurring most commonly in the gastroenteropancreatic system and the lungs. The incidence of NETs is increasing worldwide; median survival for patients with metastatic NETs is 5–65 months. A growing body of evidence shows survival benefit in patients with advanced NETs (gastroenteropancreatic and lung) treated with mTOR inhibitor everolimus, with improvement in survival being demonstrated in the clinical trial and real-world setting. Everolimus has been shown to have a manageable safety profile, with the most common adverse events being stomatitis, rash, diarrhea, fatigue and infections. Due to the rarity of the condition, there are challenges in conducting clinical trials in these patients. Further research is required to clarify the role of adjuvant therapy, treatment sequencing and the use of multimodality treatments.

Summary of emerging personalized medicine in neuroendocrine tumors: are we on track?

Neuroendocrine tumors (NETs) comprise a heterogeneous group of malignancies, with differences in prognosis and effective therapies. Traditionally, NETs have been characterized by tumor grade, site of primary tumor, functional status, and presence of underlying familial syndrome. However, increased feasibility and utilization of next-generation sequencing and other methodologies have revealed new genomic and epigenetic aberrations. In the last decade, treatment options available for metastatic well-differentiated gastroenteropancreatic (GEP) NETs have expanded, with approval of antiangiogenic and mTOR-directed targeted therapies, and our armamentarium of active therapies is likely to further increase. Cytotoxic therapies also are an important option for pancreatic NETs, and MGMT promoter methylation and protein expression may be an important biomarker for efficacy of alkylating agents. Peptide receptor radioligand therapy is an emerging treatment that uses functional imaging to personalize dosimetry to the tumor and avoid nephrotoxicity. Nevertheless, there is a critical need for further biomarkers, particularly multianalyte biomarkers, to aid in prognostication and predict efficacy of therapies.

The pivotal role of mammalian target of rapamycin inhibition in the treatment of patients with neuroendocrine tumors

Significant advances have been made toward understanding the biology of neuroendocrine tumors (NET) in terms of defining prognosis and improving clinical management; however, many unmet needs remain. The treatment landscape for NET has evolved, with the approval of the targeted agents everolimus and sunitinib for the treatment of advanced pancreatic NET in 2011 followed by the approval of everolimus for the treatment of advanced nonfunctional gastrointestinal and lung NET in 2016. Mammalian target of rapamycin (mTOR) and components of the mTOR pathway play pivotal roles in NET pathogenesis. Effects of the mTOR inhibitor everolimus have been well documented in preclinical and clinical studies, both as monotherapy and combination therapy. mTOR inhibition as backbone therapy within the NET treatment landscape is a focus of continuing research, which includes evaluation of the growing armamentarium of approved and investigational agents as potential combination partners. Data evaluating the clinical benefits of agents targeting mTOR and related pathways (alone and in combination) in the treatment of patients with NET continue to increase. Many of the findings to date are encouraging.

Unusual endoscopic findings of gastric neuroendocrine tumor

Gastric neuroendocrine tumor (NET) is sometimes found as a submucosal tumor on upper gastrointestinal endoscopy. Gastric NET with malignant profile and neuroendocrine carcinoma (NEC) show various forms which are difficult to distinguish from gastric cancer and other disease. We report a case of a cauliflower-shaped NET of the stomach. A 61-year-old man was referred to our hospital with a complaint of abdominal fullness. Upper gastrointestinal endoscopic examination revealed an unusual, whitish cauliflower-shaped tumor that belongs to Borrmann type I on the lesser curvature of the gastric antrum. Histological examination of the biopsy specimen revealed NET G2, because the tumor cells were CD56- and synaptophysin-positive by immunohistochemical analysis. A distal gastrectomy with D2 lymphadenectomy was performed. A recurrence in the liver was revealed by follow up computed tomography after 11 months from operation. Combined chemotherapy with irinotecan (CPT-11) plus cisplatin (CDDP) was treated. The patient achieved a partial response, but he died after 31 months from gastrectomy. There is no independent, large-scaled prospective study and no standard treatment for gastric NETs with distant metastases. Our case is reported with a literature review of the treatment of metastatic gastric NET G2.

Quality of life after treatment of neuroendocrine liver metastasis

BACKGROUND

A large subset of patients with neuroendocrine liver metastasis (NELM) is symptomatic at the time of presentation. In addition to improving survival, treatment of NELM seeks to provide palliation of symptoms. However, data on health-related quality of life (QoL) are uncommon. We sought to define patient-reported QoL after treatment of NELM.

METHODS

Patients who underwent treatment of NELM at Johns Hopkins Hospital between 1998 and 2013 and who were alive as of March 2014 were identified (n = 125). These patients were invited to complete a QoL survey designed using validated assessment tools, to assess their physical, mental, and general health before treatment, after the most recent treatment and at the time of the study. Clinicopathologic data were collected and correlated with QoL data.

RESULTS

The response rate was 68.0% (n = 85). Median patient age was 55 y and most were male (59.2%). Most patients had a pancreatic (24.7%) or a small bowel (37.7%) primary tumor; the overwhelming majority had multiple NELM (83.5%). Patient-reported symptoms before any treatment included diarrhea (41.1%), flushing (34.1%), fatigue (36.5%), and osteoarticular pain (18.8%). Initial treatment of NELM consisted of surgery in 55 patients (64.7%) and nonsurgical treatment in 30 patients (35.3%). Many patients reported an overall improvement in physical health and mental health. Specifically, the proportion of patients reporting diarrhea (before any treatment, 41.1% versus currently, 25.9%; P = 0.019) and flushing (before any treatment, 34.1% versus currently, 10.5%; P < 0.001) tended to decrease over time and a lower proportion of patients reported to be currently sad about being ill (before any treatment, 31.8% versus currently, 23.2%; P = 0.009). Patients with a very poor QoL at the time of the diagnosis were more likely to experience an improvement in QoL after treatment. Interestingly, there was no difference in the improvement in overall QoL whether the initial treatment for NELM was surgical or nonsurgical; however, a lower proportion of patients were dissatisfied with surgery versus nonsurgical therapy (5.4% versus 9.4%; P = 0.001).

CONCLUSIONS

Less than one-fourth of patients experienced a significant improvement in QoL after treatment of NELM. The patients who benefit the most of treatment were those who were more symptomatic before any treatment.