Streptozocin alone compared with streptozocin plus fluorouracil in the treatment of advanced islet-cell carcinoma

Gastrointestinal neuroendocrine tumors: Searching the optimal treatment strategy--A literature review

Neuroendocrine tumors of the gastro-entero-pancreatic system (GEP-NETs) are a heterogeneous group of neoplasms, with different malignant potential and behavior. Many treatment options are available. Surgery should be considered for localized tumors and in some selected cases of metastatic disease. Somatostatin analogs, useful for symptoms control in functioning tumors, are also effective to inhibit tumor progression in specific settings. The multi-TKI sunitinib and of the mTOR-inhibitor everolimus are efficacy for metastatic pancreatic NET (P-NET) treatment. Chemotherapy is generally used in symptomatic and progressive NETs. Peptide receptor radionuclide therapy (PRRT) should be recommended after failure of medical therapy. For tumors confined to the liver ablative techniques should be considered. Nevertheless a shared therapeutic sequence for GEP-NET treatment still does not exist. In this review, we analyzed available data trying to identify the better treatment strategy and to suggest potential therapeutic algorithms distinguishing P-NETs from gastrointestinal NETs (GI-NETs).

Neuroendocrine tumors of the gastrointestinal tract and the role of cytotoxic chemotherapy

Neuroendocrine tumors (NETs) comprise a heterogeneous group of tumors derived from peptide- and amine-secreting cells of the neuroendocrine system. NETs commonly arise in the gastrointestinal tract but can arise in most organs of the body. Although the incidence of NETs is not high, the prevalence is relatively high because many patients may live relatively long periods without major symptoms from the disease. Whilst many of these tumors take on an indolent clinical course, they constitute a therapeutic challenge when they progress, metastasize and become symptomatic. Treatment requires a multidisciplinary approach that may include cytotoxic chemotherapy. Almost all clinical trials investigating cytotoxic chemotherapy in NETs are small single-arm studies, hence guidelines are derived from expert opinion and from extrapolating results from small-cell lung cancer studies. This article provides a broad coverage of systemic therapies for NETs but focusses on the role of cytotoxic chemotherapy.

Streptozocin and 5-Fluorouracil for the Treatment of Pancreatic Neuroendocrine Tumors: Efficacy, Prognostic Factors and Toxicity

BACKGROUND

In our center, the combination of streptozocin (STZ) and 5-fluorouracil (5-FU) has been used as the first-line treatment in the majority of patients with pancreatic neuroendocrine tumors (pNETs) over the past few decades. The objective of the current study was to assess the efficacy, prognostic factors and safety of the combination of STZ and 5-FU.

PATIENTS AND METHODS

Medical records and radiological reports of 133 patients with pNETs who received the combination of STZ and 5-FU during the period 1981-2014 were retrospectively evaluated.

RESULTS

The median survival from the start of treatment was 51.9 months in the whole group. In the radiologically evaluable patients (n = 100), progression-free survival was 23 months. Complete response was reached in 3 patients (3%), partial response in 25 patients (25%), 64 patients (64%) had stable disease, and 8 patients (8%) had progressive disease. In a multivariate analysis, surgery of the primary tumor and having a G3 tumor were significant positive and negative prognostic factors of survival from the start of treatment, respectively. Having either a G3 tumor or a stage IV tumor were significant prognostic factors for a shorter progression-free survival. Chemotherapy had to be discontinued in 29 patients due to side effects, of which kidney toxicity (mainly grades 1-2) was the most frequent.

CONCLUSION

As shown in recent reports, the combination of STZ and 5-FU is effective in the treatment of pNETs in terms of survival and radiological response and has an acceptable toxicity profile.

Streptozocin-Based Chemotherapy in Patients with Advanced Neuroendocrine Neoplasms--Predictive and Prognostic Markers for Treatment Stratification

BACKGROUND AND AIM

Chemotherapy with streptozocin (STZ) in combination with 5-FU or doxorubicin (Dox) represents a standard of care for patients with metastatic pancreatic neuroendocrine neoplasms (pNEN). However, predictive markers for patient selection are still missing. The aim of this study was a retrospective evaluation of the clinicopathological characteristics of pNEN patients receiving STZ-based chemotherapies and to identify predictive and prognostic markers.

PATIENTS AND METHODS

We retrospectively analyzed 77 patients treated at our center between 1995 and 2013. The median overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan-Meier and Cox regression methods, respectively. Uni- and multivariate analyses were performed.

RESULTS

The median PFS (mPFS) in patients receiving STZ/5-FU/Dox was 16 months with a median OS (mOS) of 28 months. Objective response rate (ORR) and disease control rate (DCR) were 34% and 72%, respectively. Biochemical response and positive octreotide scintigraphy predicted objective response. Univariate analysis revealed Ki-67 > 10% and the absence of biochemical or objective response by imaging as independent risk factors for shorter PFS. Additionally, performance status (PS) and resection of the primary tumor were observed to influence mOS. Treatment was well tolerated with less than 10% grade 3 and 4 toxicities.

CONCLUSIONS

STZ-based chemotherapy is an effective and well-tolerated treatment option in patients with well differentiated neuroendocrine neoplasms. Positive octreotide scintigraphy and biochemical response predict objective response.

Non-functional neuroendocrine tumors of the pancreas: Advances in diagnosis and management

Nonfunctional neuroendocrine tumors of the pancreas (NF-PNETs) are a heterogeneous group of neoplasms. Although rare, the incidence of NF-PNETs is increasing significantly. The classification of PNETs has evolved over the past decades and is now based on a proliferation grading system. While most NF-PNETs are slow growing, tumors with more aggressive biology may become incurable once they progress to unresectable metastatic disease. Tumors of higher grade can be suspected preoperatively based on the presence of calcifications, hypoenhancement on arterial phase computed tomography, positron emission technology avidity and lack of octreotide scan uptake. Surgery is the only curative treatment and is recommended for most patients for whom complete resection is possible. Liver-directed therapies (thermal ablation, transarterial embolization) can be useful in controlling unresectable hepatic metastatic disease. In the presence of unresectable progressive disease, somatostatin analogues, everolimus and sunitinib can prolong progression-free survival. This article provides a comprehensive review of NF-PNETs with special emphasis on recent advances in diagnosis and management.

Everolimus and pancreatic neuroendocrine tumors (PNETs): Activity, resistance and how to overcome it

Neuroendocrine tumors (NET) are rare malignancies, with the most common site of origin being from the gastrointestinal tract, particularly the pancreas, small bowel and appendix. Pancreatic neuroendocrine tumors (PNETs) can be functional, hormone secreting tumors, and can have distinctive symptoms leading to the diagnosis. In contrast nonfunctional tumors, the majority of PNETs, usually present later either incidentally or due to tumor bulk symptoms. Currently Everolimus, an inhibitor of mammalian target of rapamycin (mTOR), is the most promising drug for patients with unresectable, metastatic disease, in progressive well-differentiated PNETs and many studies are ongoing to demonstrate its effects on the other neuroendocrine histotipes. Food and Drug Administration (FDA) and European Medicines Agency (EMA) registered Everolimus in advanced/metastatic breast cancer, in advanced/metastatic renal cell carcinoma and in well/moderately differentiated pancreatic neuroendocrine tumors. Nevertheless only a subset of patients respond to the therapy due to the development of drug resistance. Thus the powerful Everolimus antitumor activity have prompted extensive efforts to overcome drug resistance and to maximize clinical benefit. In this review we aim to summarize current knowledge on mechanisms of Everolimus and other mTOR inhibitors molecules resistance with the intent to overcome it.

Pancreatic NETs: where do we stand now?

The systemic management of patients with pancreatic neuroendocrine tumors includes chemotherapy and targeted agents such as everolimus and sunitinib. Which treatment to favor in a particular patient is not known. The most commonly used chemotherapy agents are streptozocin and temozolamide, often prescribed in combination with fluoropyrimidines. A potential biomarker for selection of temozolomide-based chemotherapy is O-6-methylguanine-DNA-methyltrasferase expression. Chemotherapy yields higher response rates and may be preferable in patients with higher-grade tumors and those who are symptomatic. The mammalian target of rapamycin inhibitor everolimus has shown improvement in progression-free survival (PFS) in a robust, well-conducted phase III study. Everolimus, however, can induce limiting toxicities that may result in treatment discontinuation and does not improve survival. However, the objective response rate is very low. Sunitinib, likewise, increases PFS but the data comes from a smaller trial which was terminated early. Sunitinib displays a different toxicity profile and is associated with a trend towards improved overall survival. It is clear that biomarkers to properly select the most effective agents in an individual patient are needed.

Streptozocin/5-fluorouracil chemotherapy is associated with durable response in patients with advanced pancreatic neuroendocrine tumours

BACKGROUND

The role of systemic chemotherapy for pancreatic neuroendocrine tumours (pNET) is controversially discussed. Objective response rates (RR) reported for streptozocin (STZ)-based chemotherapy are variable and novel targeted drugs have recently been approved. However, the sequence of treatment remains unclear. We aimed to evaluate the efficacy of STZ plus 5-fluorouracil (STZ/5-FU) in a large pNET cohort.

METHODS

Data from 96 pNET patients treated with STZ/5-FU were analysed retrospectively. Endpoints of the study were RR, time to tumour progression (TTP) and overall survival (OS).

RESULTS

Mean age of patients at the start of chemotherapy was 57.6years (range, 32.1-80.4). STZ/5-FU was the 1st line treatment in 56.3%. 11.5% had G1, 79.2% G2 and 6.3% G3 neoplasms. Baseline progression was evident in 74%. Objective response rate was 42.7%. 40.6% of patients showed stable disease as best response while 16.7% showed progressive disease. Treatment was discontinued due to toxicity in 16 patients. Median TTP and OS were 19.4 (95% confidence interval (CI), 13.6-25.2) and 54.8months (95% CI, 34.7-74.9), respectively. In Cox regression analysis, Ki67>15% was the only negative prognostic factor for TTP (hazard ratio (HR), 3.3; P<0.001), confirmed by multivariate analysis (HR, 6.7; P=0.001).

CONCLUSIONS

STZ/5-FU was associated with considerable RR. Treatment was associated with durable TTP especially in patients with Ki67-index of ⩽15%. These findings along with good tolerability strengthen the value of this two-drug chemotherapy for the management of unresectable pNET.

Impact of prior chemotherapy use on the efficacy of everolimus in patients with advanced pancreatic neuroendocrine tumors: a subgroup analysis of the phase III RADIANT-3 trial

OBJECTIVE

The aim of this study was to evaluate efficacy and safety of everolimus in patients with pancreatic neuroendocrine tumors (pNET) by prior chemotherapy use in the RAD001 in Advanced Neuroendocrine Tumors, Third Trial (RADIANT-3).

METHODS

Patients with advanced, progressive, low- or intermediate-grade pNET were prospectively stratified by prior chemotherapy use and World Health Organization performance status and were randomly assigned (1:1) to everolimus 10 mg/d (n = 207) or placebo (n = 203).

RESULTS

Of the 410 patients, 204 (50%) were naive to chemotherapy (chemonaive). Baseline characteristics were similar for patients with or without prior chemotherapy. Everolimus significantly prolonged median progression-free survival regardless of prior chemotherapy use (prior chemotherapy: 11.0 vs 3.2 months; hazard ratio, 0.34; 95% confidence interval, 0.25-0.48; P < 0.0001) (chemonaive: 11.4 vs 5.4 months; hazard ratio, 0.42; 95% confidence interval, 0.29-0.60; P < 0.0001). Stable disease was the best overall response in 73% of everolimus-treated patients (151/207). The most common drug-related adverse events included stomatitis (60%-69%), rash (47%-50%), and diarrhea (34%).

CONCLUSIONS

As more treatment options become available, it is important to consider the goals of treatment and to identify patients who would potentially benefit from a specific therapy. Findings from this planned subgroup analysis suggest the potential for first-line use of everolimus in patients with advanced pNET.

Streptozocin chemotherapy for advanced/metastatic well-differentiated neuroendocrine tumors: an analysis of a multi-center survey in Japan

BACKGROUND

Neuroendocrine tumors (NETs) are believed to be relatively rare and to follow a generally indolent course. However, liver metastases are common in NET patients and the outcome of NET liver metastasis is poor. In Western countries, streptozocin (STZ) has been established as a first-line anticancer drug for unresectable NET; however, STZ cannot be used in daily practice in Japan. The aim of the present study was to determine the status of STZ usage in Japan and to evaluate the effectiveness and safety of STZ chemotherapy in Japanese NET patients.

METHODS

A retrospective multi-center survey was conducted. Five institutions with experience performing STZ chemotherapy participated in the study. The patient demographics, tumor characteristics, context of STZ chemotherapy, and patient outcome were collected and assessed.

RESULTS

Fifty-four patients were enrolled. The main recipients of STZ chemotherapy were middle-aged patients with pancreatic NET and unresectable liver metastases. The predominant regimen was the weekly/bi-weekly intravenous administration of STZ combined with other oral anticancer agents. STZ monotherapy was used in one-fourth of the patients. The median progression-free and overall survival periods were 11.8 and 38.7 months, respectively, and sustained stable disease was obtained in some selected patients. The adverse events profile was mild and tolerable.

CONCLUSIONS

Our survey showed the clinical benefit and safety of STZ therapy for Japanese patients with unresectable NET. Therefore, we recommend that STZ, which is the only cytotoxic agent available against NET, should be used in daily practice in Japan.

Genetics of pancreatic neuroendocrine tumors: implications for the clinic

Pancreatic neuroendocrine tumors (PanNETs) are a common and deadly neoplasm of the pancreas. Although the importance of genetic alterations in PanNETs has been known for many years, recent comprehensive sequencing studies have greatly expanded our knowledge of neuroendocrine tumorigenesis in the pancreas. These studies have identified specific cellular processes that are altered in PanNETs, highlighted alterations with prognostic implications, and pointed to pathways for targeted therapies. In this review, we will discuss the genetic alterations that play a key role in PanNET tumorigenesis, with a specific focus on those alterations with the potential to change the way patients with these neoplasms are diagnosed and treated.

Update on pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are relatively rare tumors comprising 1-2% of all pancreas neoplasms. In the last 10 years our understanding of this disease has increased dramatically allowing for advancements in the treatment of pNETs. Surgical excision remains the primary therapy for localized tumors and only potential for cure. New surgical techniques using laparoscopic approaches to complex pancreatic resections are a major advancement in surgical therapy and increasingly possible. With early detection being less common, most patients present with metastatic disease. Management of these patients requires multidisciplinary care combining the best of surgery, chemotherapy and other targeted therapies. In addition to surgical advances, recently, there have been significant advances in systemic therapy and targeted molecular therapy.

Consensus Recommendations for the Diagnosis and Management of Pancreatic Neuroendocrine Tumors: Guidelines from a Canadian National Expert Group

Pancreatic neuroendocrine tumors (pNETs) are rare heterogeneous tumors that have been steadily increasing in both incidence and prevalence during the past few decades. Pancreatic NETs are categorized as functional (F) or nonfunctional (NF) based on their ability to secrete hormones that elicit clinically relevant symptoms. Specialized diagnostic tests are required for diagnosis. Treatment options are diverse and include surgical resection, intraarterial hepatic therapy, and peptide receptor radionuclide therapy (PRRT). Systemic therapy options include targeted agents as well as chemotherapy when indicated. Diagnosis and management should occur through a collaborative team of health care practitioners well-experienced in managing pNETs. Recent advances in pNET treatment options have led to the development of the Canadian consensus document described in this report. The discussion includes the epidemiology, classification, pathology, clinical presentation and prognosis, imaging and laboratory testing, medical and surgical management, and recommended treatment algorithms for pancreatic neuroendocrine cancers.

Bevacizumab combined with 5-FU/streptozocin in patients with progressive metastatic well-differentiated pancreatic endocrine tumours (BETTER trial)--a phase II non-randomised trial

AIM OF THE STUDY

Neuroendocrine tumours are highly vascular neoplasms known to overexpress vascular endothelial growth factor (VEGF) and its receptor. Bevacizumab, an inhibitor of VEGF, was assessed in combination with chemotherapy in pancreatic neuroendocrine tumour (P-NET).

PATIENTS AND METHODS

BETTER was a multicentre, open-label, non-randomised, two-group phase II trial. Patients with progressive metastatic, well-differentiated P-NET received a minimum of 6 month treatment of bevacizumab at 7.5 mg/kg IV on d1 q3w with 5-FU at 400 mg/m2/day and streptozocin at 500 mg/m2/day IV from d1 to d5 every 42 days. The primary end-point was progression-free survival (PFS); secondary end-points were overall survival (OS), overall response rate, safety and quality of life.

RESULTS

A total of 34 patients were included. Median age was 55 years, 65% of patients were men, 97% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and 97% had a Ki-67 proliferative index of <15%. After a maximum of 24 month follow-up per patient, the median PFS assessed by investigators was 23.7 months [95% confidence interval (CI): 13.1; not reached], 19 (56%) patients had a partial response and 15 (44%) had stable disease as best response. OS rate at 24 months was 88%. The most frequently reported grade 3-4 adverse events were hypertension (21% patients), abdominal pain (12%) and thromboembolic events (9%).

CONCLUSION

Bevacizumab with 5-FU/streptozocin in the treatment of pancreatic NETs seems to be feasible with a PFS of 23.7 months, which deserves further attention. No unexpected toxicity was observed.

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.

Metronomic capecitabine in gastroenteropancreatic neuroendrocrine tumors: a suitable regimen and review of the literature

Background

We present a retrospective analysis of metronomic capecitabine in metastatic gastroenteropancreatic neuroendrocrine tumors (GEP-NETs). A review of the literature is also presented.

Methods

From January 2007 to December 2013, ten patients with metastatic GEP-NETs (four pancreatic and six ileal) who progressed after treatment with somatostatin analogs and other cytotoxic agents received oral capecitabine 1,500 mg/day continuously. The median patient age was 68 (range 29–82) years. The median treatment duration was 8 months.

Results

Five (50%) patients achieved a partial radiographic response, four (40%) showed stable disease, and one (10%) progressed. Median overall survival was 56 months. Three of the four pancreatic patients achieved a partial radiographic response that lasted for a median of 15.5 months; overall survival and progression-free survival in this subgroup was 58 and 6 months, respectively.

Conclusion

Data in the literature show that capecitabine has only occasionally been used as a single agent, with increased toxicity. Only one study using single-agent capecitabine reported a progression-free survival of 9.9 months and overall survival of 36.5 months, without an objective response or major toxicity. In our experience, metronomic capecitabine was well tolerated, although minor side effects may have been underestimated due to the retrospective nature of our study. This regimen also seems to be feasible in elderly people. Although high response rates and prolonged response duration indicate the potential efficacy of this treatment, our results should be interpreted cautiously because of the small number of patients involved. Capecitabine was most effective in the pancreatic subgroup, which would seem to be more sensitive to chemotherapy.

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

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

Nordic guidelines 2014 for diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

BACKGROUND

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

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.

SEOM clinical guidelines for the diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) 2014

GEP-NENs are a challenging family of tumors of growing incidence and varied clinical management and behavior. Diagnostic techniques have substantially improved over the past decades and significant advances have been achieved in the understanding of the molecular pathways governing tumor initiation and progression. This has already translated into relevant advances in the clinic. This guideline aims to provide practical recommendations for the diagnosis and treatment of GEP-NENs. Diagnostic workup, histological and staging classifications, and the different available therapeutic approaches, including surgery, liver-directed ablative therapies, peptide receptor radionuclide therapy, and systemic hormonal, cytotoxic or targeted therapy, are briefly discussed in this manuscript. Clinical presentation (performance status, comorbidities, tumor-derived symptoms and hormone syndrome in functioning tumors), histological features [tumor differentiation, proliferation rate (Ki-67), and expression of somatostatin receptors], disease localization and extent, and resectability of primary and metastatic disease, are all key issues that shall be taken into consideration to appropriately tailor therapeutic strategies and surveillance of these patients.

Nonsurgical Strategies in Patients With NET Liver Metastases: A Protocol of Four Systematic Reviews

BACKGROUND

Patients diagnosed with neuroendocrine tumors (NETs) with hepatic metastases generally have a worse prognosis as compared with patients with nonmetastasized NETs. Due to tumor location and distant metastases, a surgical approach is often not possible and nonsurgical therapeutic strategies may apply.

OBJECTIVE

The aim of these systematic reviews is to evaluate the role of nonsurgical therapy options for patients with nonresectable liver metastases of NETs.

METHODS

An objective group of librarians will provide an electronic search strategy to examine the MEDLINE, EMBASE, and The Cochrane Library (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials [CENTRAL]) databases. There will be no restriction concerning language and publication date. The qualitative and quantitative synthesis of the systematic review will be conducted with randomized controlled trials (RCT), prospective, and retrospective comparative cohort, and case-control studies. Case series will be collected in a separate database and only used for descriptive purposes.

RESULTS

This study is ongoing and presents a protocol of four systematic reviews to assess the role of nonsurgical treatment options in patients with neuroendocrine liver metastases.

CONCLUSIONS

These systematic reviews, performed according to this protocol, will assess the value of noninvasive therapy options for patients with nonresectable liver metastases of NETs in combination with invasive techniques, such as percutaneous liver-directed techniques and local ablation techniques.

TRIAL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO): CRD42012002657; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2657 (Archived by WebCite at http://www.webcitation.org/6NDlYi37O); CRD42012002658; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2658 (Archived by WebCite at http://www.webcitation.org/6NDlfWSuD); CRD42012002659; www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2659 (Arichived by Webcite at http://www.webcitation.org/6NDlmWAFM); and CRD42012002660; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2660 (Archived by WebCite at http://www.webcitation.org/6NDmnylzp).

Outcome of peptide receptor radionuclide therapy with 177Lu-octreotate in advanced grade 1/2 pancreatic neuroendocrine tumours

PURPOSE

The clinical benefit of peptide receptor radionuclide therapy (PRRT) in patients with pancreatic neuroendocrine tumours (pNET) has not yet been well described and defined in its full extent due to limited data in this tumour subgroup. This study was intended to obtain robust, comparative data on the outcome and toxicity of standardized PRRT with (177)Lu-octreotate in a well-characterized population of patients with advanced pNET of grade 1/2 (G1/2).

METHODS

We retrospectively analysed a cohort of 68 pNET patients with inoperable metastatic disease consecutively treated with (177)Lu-octreotate (four intended cycles at 3-monthly intervals; mean activity per cycle 8.0 GBq). Of these 68 patients, 46 (67.6 %) had documented morphological tumour progression during the 12 months before initiation of treatment, and PRRT was the first-line systemic therapy in 35 patients (51.5 %). Response was evaluated according to modified Southwest Oncology Group (SWOG) criteria and additionally with Response Criteria in Solid Tumors (RECIST) 1.1. Survival was analysed using Kaplan-Meier curves and Cox proportional hazards model for univariate and multivariate analyses. Toxicity was assessed by standard follow-up laboratory work-up including blood count, and liver and renal function, supplemented with serial (99m)Tc-DTPA clearance measurements.

RESULTS

The median follow-up period was 58 months (range 4 - 112). Reversible haematotoxicity (grade 3 or more) occurred in four patients (5.9 %). No significant nephrotoxicity (grade 3 or more) was observed. Treatment responses (SWOG criteria) consisted of a partial response in 41 patients (60.3 %), a minor response in 8 (11.8 %), stable disease in 9 (13.2 %), and progressive disease in 10 (14.7 %). Median progression-free survival (PFS) and overall survival (OS) were 34 (95 % CI 26 - 42) and 53 months (95 % CI 46 - 60), respectively. A G1 proliferation status was associated with longer PFS (p = 0.04) and OS (p = 0.044) in the multivariate analysis. Variables linked to impaired OS, on the other hand, were a reduced performance status (Karnofsky score ≤ 70 %, p = 0.007), a high hepatic tumour burden (≥ 25 % liver volume, p = 0.017), and an elevated plasma level of neuron-specific enolase (NSE >15 ng/ml, p = 0.035).

CONCLUSION

The outstanding response rates and survival outcomes suggest that PRRT is highly effective in advanced G1/2 pNET when compared to data of other treatment modalities. Independent predictors of survival are the tumour proliferation index, the patient's performance status, tumour burden and baseline plasma NSE level.

Capecitabine and streptozocin ± cisplatin in advanced gastroenteropancreatic neuroendocrine tumours

BACKGROUND

Cytotoxic chemotherapy is widely used for advanced, unresectable pancreatic and other gastrointestinal foregut neuroendocrine tumours (NETs) and the most commonly used regimen combines 5-fluorouracil with streptozocin. The NET01 trial was designed to investigate whether capecitabine combined with streptozocin was an acceptable regimen with or without adding cisplatin.

METHODS

Patients with advanced, unresectable NETs of pancreatic, gastrointestinal foregut or unknown primary site were randomised to receive three-weekly capecitabine (Cap) 625 mg/m(2) twice daily orally, streptozocin (Strep) 1.0 g/m(2) intravenously on day 1, with or without cisplatin (Cis) 70 mg/m(2) intravenously on day 1. The primary outcome measure was objective response. Secondary outcome measures included progression-free and overall survival, quality of life, toxicity and biochemical response.

RESULTS

86 (44 CapStrep, 42 CapStrepCis) patients were randomised. Best objective response rate was 12% (95% confidence interval (CI)=2-22%) with CapStrep and 16% (95% CI=4-27.4%) with CapStrepCis. Disease-control rate was 80% with CapStrep and 74% with CapStrepCis. The estimated median progression-free and overall survival were 10.2 and 26.7 months for CapStrep and 9.7 and 27.5 months for CapStrepCis. 44% of CapStrep and 68% of CapStrepCis patients experienced grade ≥3 adverse events.

INTERPRETATION

The efficacies of the novel CapStrep±Cis regimens were very similar. CapStrep was better tolerated than CapStrepCis. The trial was registered as EudraCT: 2004-005202-71 and ISRCTN: 35124268.

Emerging therapies and latest development in the treatment of unresectable pancreatic neuroendocrine tumors: an update for clinicians

Pancreatic neuroendocrine tumors (pNETs) differ in their clinical behavior, presentation and prognosis based on their initial histological features and disease stage. While small resectable tumors can be treated surgically, metastatic and locally advanced disease carries a significant mortality and treatment options have been limited in terms of their efficacy. Streptozocin-based regimens were the only agents available before but recent advances have improved the armamentarium to treat pNETs. Newer chemotherapeutic agents such as temozolomide, somatostatin analogs and targeted therapies including everolimus and sunitinib are now available to treat these tumors. Several combination regimens with targeted therapies and newer agents such as pazopanib are being developed and tested in ongoing trials.

Eastern Canadian Colorectal Cancer Consensus Conference: standards of care for the treatment of patients with rectal, pancreatic, and gastrointestinal stromal tumours and pancreatic neuroendocrine tumours

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Halifax, Nova Scotia, October 20-22, 2011. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of rectal cancer, including pathology reporting, neoadjuvant systemic and radiation therapy, surgical techniques, and palliative care of rectal cancer patients. Other topics discussed include multidisciplinary cancer conferences, treatment of gastrointestinal stromal tumours and pancreatic neuroendocrine tumours, the use of folfirinox in pancreatic cancer, and treatment of stage ii colon cancer.

Neuroendocrine neoplasms of the GI tract: the role of cytotoxic chemotherapy

Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of neoplasms derived from peptide- and amine-secreting cells of the neuroendocrine system. NENs commonly arise in the GI tract but can arise in most organs of the body. NENs in different organs share many common pathologic features. Although the incidence of NENs is not high, the prevalence is not low because many patients may live relatively long periods without major symptoms from the disease. While many of these tumors lead an indolent clinical course, they constitute a therapeutic challenge when they progress, metastasize and become symptomatic. Treatment requires a multidisciplinary approach including cytotoxic chemotherapy. Almost all clinical trials investigating cytotoxic chemotherapy in NENs are small single-arm studies and guidelines are derived from expert opinion and from extrapolating results from small cell lung cancer studies. This article briefly reviews NENs before focusing on reviewing data on the role of cytotoxic chemotherapy studies in NENs.

Multiple cardiac metastases from a nonfunctioning pancreatic neuroendocrine tumor

Pancreatic neuroendocrine tumors (pNETs) are rare neoplasms, which most commonly metastasize to the liver. However, intrathoracic metastases from pNETs are encountered infrequently. This report describes a case of nonfunctioning pNET with multiple cardiac metastases. A 56-year-old male presented with a palpable abdominal mass that showed progressive enlargement. Findings on computed tomography (CT) of the abdomen revealed two relatively well-marginated inhomogeneous low-attenuation masses, one in the head of the pancreas and the other in the tail. Multiple enhancing masses in the left pericardium with myocardial involvement were observed on chest CT and transthoracic echocardiography. Needle biopsies were performed on the mass in the tail of the pancreas and the left ventricular apical pericardium; histologic examination by hematoxylin and eosin morphology and immunohistochemical staining showed pNET in both. This is the first report of pNET with multiple cardiac metastases to previously undescribed metastatic sites.

Clinical pathways for pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) represent a group of diseases that pose diagnostic and therapeutic challenges due to their clinical and pathological heterogeneity as well as the limited number of patients available for clinical trials. Over the last couple of decades, a major progress in understanding tumor biology led to the discovery of new potential targets for the medical treatment of these tumors.

DISCUSSION

There are numerous novel targeted agents in various stages of preclinical and clinical development that offer considerable promise as monotherapy or combination therapy for PNETs. The question of whether traditional clinical research methods are appropriate for the development of novel, targeted anticancer agents has been the subject of many discussions. Major challenges include identifying a valid target, the most effective agent within a target class, the right subset of population to benefit from the drug, and the most appropriate setting to use the drug. As new agents emerge, oncologists are faced with making clinical decisions sometimes before having a high level of evidence. In this review, we attempt to address some of the management steps involved in treating patients with pancreatic neuroendocrine tumors, particularly well to moderately differentiated tumors. The purpose of this review is to offer a therapeutic sequence including surgery, liver-directed therapy, chemotherapy, and targeted therapy for this disease.

Neuroendocrine tumours: cracking the epigenetic code

The field of epigenetics has evolved rapidly over recent years providing insight into the tumorigenesis of many solid and haematological malignancies. Determination of epigenetic modifications in neuroendocrine tumour (NET) development is imperative if we are to improve our understanding of the biology of this heterogenous group of tumours. Epigenetic marks such as DNA methylation at RASSF1A are frequent findings in NETs of all origins and may be associated with worse prognosis. MicroRNA signatures and histone modifications have been identified which can differentiate subtypes of NET and distinguish NET from adenocarcinoma in cases of diagnostic uncertainty. Historically, candidate gene-driven approaches have yielded limited insight into the epigenetics of NET. Recent progress has been facilitated by development of high-throughput tools including second-generation sequencing and arrays for analysis of the 'epigenome' of tumour and normal tissue, permitting unbiased approaches such as exome sequencing that identified mutations of chromatin-remodelling genes ATRX/DAXX in 44% of pancreatic NETs. Epigenetic changes are reversible and therefore represent an attractive therapeutic target; to date, clinical outcomes of epigenetic therapies in solid tumours have been disappointing; however, in vitro studies on NETs are promising and further clinical trials are required to determine utility of this class of novel agents. In this review, we perform a comprehensive evaluation of epigenetic changes found in NETs to date, including rare NETs such as phaeochromocytoma and adrenocortical tumours. We suggest priorities for future research and discuss potential clinical applications and novel therapies.

Pharmacokinetics and pharmacodynamics of sunitinib for the treatment of advanced pancreatic neuroendocrine tumors

INTRODUCTION

Despite being the second most common malignancy of the pancreas, pancreatic neuroendocrine tumors (PNET) have long been understudied due to their low incidence and heterogeneous clinical presentation. Emerging data from a Phase III trial demonstrates improved progression-free survival of patients with advanced PNET on treatment with sunitinib .

AREAS COVERED

This article reviews the role of sunitinib, a multitargeted tyrosine kinase inhibitor with potent antiangiogenic and antitumor effects, in the clinical management of PNET. Furthermore, the authors also discuss the pharmacokinetics and pharmacodynamics as well as other clinically relevant aspects regarding sunitinib.

EXPERT OPINION

A recent Phase III clinical trial of sunitinib demonstrated significant improvement of progression-free survival in patients with advanced or metastatic well-differentiated PNET that led to its approval in several countries, including Europe and United States. This marks a significant step forward in the clinical management of this disease and spurs hopes to further improve overall survival in this once difficult-to-treat set of patients in the coming years. Fields of future interest will include evaluation of combinatorial regimens, including conventional cytotoxic agents as well as additional targeted drugs in order to overcome resistance to sunitinib.

Therapeutic effect of sunitinib malate and its influence on blood glucose concentrations in a patient with metastatic insulinoma

Standard cytotoxic chemotherapy has limited efficacy in advanced insulinomas, and control of blood glucose concentrations in these patients may be difficult. This article describes an elderly (74-year-old) man with metastatic insulinoma and severe hypoglycemia who was treated with repeated 6-week cycles of oral sunitinib malate (25 mg/day for 4 weeks, followed by 2 weeks off treatment). After treatment for more than 2 years, his condition improved and he continued to have a good quality of life with no evidence of tumor progression based on PET/CT findings. Although sunitinib treatment lowered the patient's blood glucose concentrations further and induced repeated symptomatic hypoglycemic episodes, he was able to tolerate the treatment well after changing the timing of sunitinib dosing and adjusting his diet.

Management of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors account for 1% to 2% of pancreatic neoplasms and may occur sporadically or as part of a hereditary syndrome. Patients may present with symptoms related to hormone secretion by functional tumors or to locally advanced or metastatic nonfunctional tumors. Asymptomatic pancreatic neuroendocrine tumors are increasingly detected incidentally during abdominal imaging performed for other reasons. The management of localized pancreatic neuroendocrine tumors is surgical resection. Hepatic metastases are common and their management involves a variety of liver-directed therapies, which should be tailored according to extent of disease, symptoms, presence of extrahepatic metastases, and patient performance status.

Everolimus in advanced pancreatic neuroendocrine tumors: the clinical experience

The incidence of neuroendocrine tumors (NET) has increased dramatically in the past 30 years. This information has revitalized basic and clinical research into the molecular biology of NET and has resulted in the recent approval of new therapies for pancreatic NET (pNET), including the oral inhibitor of the mTOR everolimus. Everolimus significantly improved progression-free survival among patients with pNET in the phase III RADIANT-3 study. Here, we review the clinical studies showing the efficacy of everolimus in pNET and summarize the translational science from these studies. To understand the mechanisms of resistance and cause of treatment failure, we compared the type of progression events observed in the everolimus and placebo arms of the RADIANT-3 study. Comparison of the everolimus arm to the placebo arm indicated the fractions of progression events due to new metastasis only (21% vs. 22%), growth of preexisting lesions only (54% vs. 49%), and new metastasis along with growth of preexisting lesions (24% vs. 27%) were similar. These results suggest that although everolimus delays disease progression in patients with pNET, patients who experience disease progression while on everolimus do not appear to have a more aggressive metastatic phenotype than those whose disease progresses while on placebo.

Brain carcinoid metastases: outcomes and prognostic factors

OBJECT

Carcinoid tumors are rare and have generally been regarded as indolent neoplasms. Systemic disease is often incurable; however, patients may live years with this disease. Furthermore, metastatic brain lesions are extremely uncommon. As such, few series have examined outcomes and prognostic factors in those with brain involvement.

METHODS

The authors performed a retrospective review of patients who underwent primary treatment at Mayo Clinic in Rochester, Minnesota, for metastatic carcinoid tumors to the brain between 1986 and 2011. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier statistics. Cox proportional hazards were used to determine predictors of survival.

RESULTS

Fifteen patients underwent primary treatment for metastatic carcinoid tumors to the brain between 1986 and 2011. Their mean age was 58 ± 12 years. Eighty percent (n = 12) of patients underwent surgery, whereas 2 received stereotactic radiosurgery and 1 had whole-brain radiation therapy (WBRT) as the primary treatment. The median follow-up duration was 19 months (maximum 124 months). Systemic disease progression occurred in 73% and was the leading cause of death in known cases, while intracranial disease recurred in 40%. The median PFS and OS were 21 and 19 months, respectively. The use of adjuvant WBRT correlated with improved PFS (HR 0.15, CI 0.0074-0.95, p = 0.044). Those who underwent surgery as primary modalities trended toward longer progression-free intervals (p = 0.095), although this did not reach significance.

CONCLUSIONS

Metastatic carcinoid disease to the brain appears to have a worse prognosis than that of other extracranial metastases. Although there was a trend toward a survival advantage in patients who underwent surgery and WBRT, further study is needed to establish definitive treatment recommendations.

Pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pancreatic NETs) are rare, low- to intermediate-grade neoplasms thought to arise from the pancreatic islets. Recent advances in pathology and our understanding of the biological behavior of this group of tumors has resulted in changes in their nomenclature and how we treat them. This review puts into perspective our current understanding of pancreatic NETs in terms of their incidence, pathology, and management.

Intervention in gastro-enteropancreatic neuroendocrine tumours

Neuroendocrine tumours require dedicated interventions to control their capacity to secrete hormones but also, antitumour growth strategies. Recommendations for early interventions in NET include the management of hormone-related symptoms and poorly differentiated neuroendocrine carcinomas. In contrast, prognostic heterogeneity is a key feature of well differentiated NET that complexified the antitumour strategy whatever the stage in this subgroup of tumour. In this review, timely therapeutic interventions to control hormone-related symptoms and tumour growth in GEP NET patients are discussed. The necessity of controlling hormone-related symptoms as the first step of any strategy affects also the tumour growth control strategy. In the absence of cure at the metastatic stage, progresses are expected in the recognition of well differentiated NET subgroups that display either excellent or poor prognosis.

Selecting patients for cytotoxic therapies in gastroenteropancreatic neuroendocrine tumours

Gastroenteropancreatic neuroendocrine tumours (GEP-NET) have heterogenic clinical presentations. The majority of GEP-NET tumours have an indolent behaviour, but patients will eventually develop symptoms of tumour progression or hormone secretion that may require systemic medical interventions. Cytotoxic chemotherapy has been tested in GEP-NETs since the 80s, but treatment recommendations are controversial in many instances. Patient selection is mandatory for optimal use of chemotherapy. Important prognostic factors such as primary tumour site, tumour differentiation, tumour staging and proliferation index have been identified and validated in retrospective and prospective series. The combination of those factors and the natural history of GEP-NET provide valuable information with respect to treatment planning. In this report we provide treatment recommendations to improve systemic therapy in patients with advanced GEP-NETs based on a comprehensive review of the literature.

Relationship between clinical characteristics and survival of gastroenteropancreatic neuroendocrine neoplasms: A single-institution analysis (1995-2012) in South China

BACKGROUND

Gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine tumors accounting for 65-75% of neuroendocrine neoplasms (NENs). Given the fact that there are few studies on GEP-NENs among Chinese patients, we performed a retrospective study in South China.

METHODS

Totally 178 patients with GEP-NENs treated at the First Affiliated Hospital of Sun Yat-sen University between January 1995 and May 2012 were analyzed retrospectively.

RESULTS

Pancreas was found the most common site of involvement (34.8%). 149 patients (83.7%) presented as non-functional tumors with non-specific symptoms such as abdominal pain (33.7%); carcinoid syndrome was not found in this study. Several methods are useful for localization of GEP-NENs, yielding varied detection rates from 77.8% to 98.7%. Positive rates of chromogranin A (CgA) and synaptophysin (Syn) immunhistochemically were 69.1% and 90.2%, respectively. 87 patients (51.5%) had G1 tumors, 31(18.3%) G2 tumors and 51 (30.2%) G3 tumors. Neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC) were 69.8%, 27.2% and 3.0%, respectively. 28.1% of patients presented with distant disease. Surgery was performed in 152 (85.4%) patients, and overall 5-year survival rate was 54.5%. Functionality, G1 grading and NET classification were associated with favorable prognosis in univariate analysis. Distant metastasis contributed to unfavorable prognosis of these tumors.

CONCLUSIONS

Nonfunctional tumors with non-specific symptoms account for the majority of GEP-NENs. Diagnosis depends on pathological classification. Multidisciplinary treatments could help improve the outcome.

Relationship between clinical characteristics and survival of gastroenteropancreatic neuroendocrine neoplasms: A single-institution analysis (1995-2012) in South China

BACKGROUND

Gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine tumors accounting for 65-75% of neuroendocrine neoplasms (NENs). Given the fact that there are few studies on GEP-NENs among Chinese patients, we performed a retrospective study in South China.

METHODS

Totally 178 patients with GEP-NENs treated at the First Affiliated Hospital of Sun Yat-sen University between January 1995 and May 2012 were analyzed retrospectively.

RESULTS

Pancreas was found the most common site of involvement (34.8%). 149 patients (83.7%) presented as non-functional tumors with non-specific symptoms such as abdominal pain (33.7%); carcinoid syndrome was not found in this study. Several methods are useful for localization of GEP-NENs, yielding varied detection rates from 77.8% to 98.7%. Positive rates of chromogranin A (CgA) and synaptophysin (Syn) immunhistochemically were 69.1% and 90.2%, respectively. 87 patients (51.5%) had G1 tumors, 31(18.3%) G2 tumors and 51 (30.2%) G3 tumors. Neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC) were 69.8%, 27.2% and 3.0%, respectively. 28.1% of patients presented with distant disease. Surgery was performed in 152 (85.4%) patients, and overall 5-year survival rate was 54.5%. Functionality, G1 grading and NET classification were associated with favorable prognosis in univariate analysis. Distant metastasis contributed to unfavorable prognosis of these tumors.

CONCLUSIONS

Nonfunctional tumors with non-specific symptoms account for the majority of GEP-NENs. Diagnosis depends on pathological classification. Multidisciplinary treatments could help improve the outcome.

Safety and efficacy of sunitinib in patients with unresectable pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are becoming increasingly common, with the majority of patients presenting with either lymph node involvement or metastatic disease, thus requiring systemic therapy. Targeted therapy is a type of medication that blocks the growth of cancer cells by interfering with specific targeted molecules needed for carcinogenesis and tumor growth rather than by simply interfering with rapidly dividing cells (eg, with traditional chemotherapy). In this review article, pharmacologic inhibition of multiple targets including vascular endothelial growth factor receptor (VEGF-R), platelet-derived growth factor receptor (PDGF-R), stem cell factor receptor (c-KIT-R), FML-like tyrosine kinase-3 receptor (FLT3-R), colony stimulating factor 1 receptor (CSF1-R), and glial cell-line derived neurotrophic factor receptor (RET-R) with sunitinib in patients with unresectable PNETs is discussed. Phase III data indicate that additional treatment with sunitinib can improve prognosis in these patients.