Radioembolization for unresectable neuroendocrine hepatic metastases using resin 90Y-microspheres: early results in 148 patients. Am J Clin Oncol. 2008;31:271-279. [PMID: 18525307 DOI: 10.1097/coc.0b013e31815e4557]

Neuroendocrine pancreatic tumors: guidelines for management and update

Pancreatic neuroendocrine tumors (PanNETs) are a diverse group of rare neoplasms. Commonly referred to as islet cell tumors, PanNETs are classified as functional or nonfunctional depending on their production of specific pancreatic endocrine hormones (e.g. insulin, gastrin, glucagon, and others) and association with the resultant clinical syndromes. While most PanNETs are sporadic, syndromic patients, in particular those with multiple endocrine neoplasia type 1 (MEN-1) and von Hippel Lindau (VHL), are at increased risk of developing these tumors. Recent investigations of patients with sporadic and syndromic PanNETs have elucidated critical pathways in tumor development, such as mammalian target of rapamycin (mTOR) signaling and its downstream growth factors such as vascular endothelial growth factor (VEGF). Prognosis ranges from favorable for localized, low-grade neoplasms to poor for advanced, high-grade tumors. Regardless of the stage at presentation, surgery is the first-line therapy for patients with disease amenable to surgical resection. We favor formal pancreatectomy with conventional lymph node sampling for the vast majority of patients, either through open or laparoscopic techniques. Those with insulinomas, however, may be candidates for enucleation. Cytoreductive surgery is also recommended for patients with locoregional recurrences or hepatic metastases. Regional adjuvants such as radiofrequency ablation (RFA), transarterial chemoembolization (TACE), and others are often employed in an attempt to palliate symptoms and prolong survival. Unfortunately, cytotoxic chemotherapy has been largely ineffective in treating patients with PanNETs. The somatostatin analogue octreotide, however, has been effective in palliating symptoms and slowing the progression of disease. Other promising systemic agents, including sunitinib and everolimus, have targeted critical PanNET signaling pathways. In summary, surgery remains the principal therapeutic strategy for patients with PanNETs, but continued research may identify more robust systemic therapies for those with advanced disease.

Treatment options for unresectable neuroendocrine liver metastases

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Liver-directed therapies in liver metastases from neuroendocrine tumors of the gastrointestinal tract

Presence of liver metastases in neuroendocrine tumors is a major factor altering both quality of life and prognosis. Surgery is recognized as the sole curative treatment. When it is not possible, radiological directed therapies are crucial, particularly in liver metastases from the small bowel. Thermal ablative therapies as radiofrequency ablation and microwave are alternative treatments alone or in combination with surgery. Hepatic artery embolization or chemoembolization, as radioembolization, has been shown to have good clinical, biochemical, and morphological responses when liver burden does not permit ablative therapies. However, technical issues are multiple and there is no randomized study to compare their efficacy. The choice of management depends on liver burden and metastases pattern, but also on origin of the primary tumor, tumor differentiation, and tumor proliferative activity. These patients should benefit of a multidisciplinary management to limit morbidity and mortality.

Comprehensive review of the diagnosis and treatment of biliary tract cancer 2012. Part II: multidisciplinary management

Biliary tract cancers (gallbladder cancer, intra- and extra-hepatic cholangiocarcinoma and selected periampullary cancers) accounted for 12,760 new cases of cancer in the USA in 2010. These tumors have a dismal prognosis with most patients presenting with advanced disease. Early, accurate diagnosis is essential, both for potential cure where possible and for optimal palliative therapy in all others. This review examines the currently available and emerging technologies for diagnosis and treatment of this group of diseases.

Treatment of liver metastases in patients with neuroendocrine tumors of gastroesophageal and pancreatic origin

Well-to-moderately differentiated neuroendocrine tumors of gastroesophageal and pancreatic origin (GEP-NETs) with liver metastasis are a heterogeneous group of malignancies for which a range of therapeutic options have been employed. Surgical resection of hepatic metastases or hepatic artery embolization may be beneficial in patients with hepatic-predominant metastatic disease. Patients with "carcinoid" syndrome and syndromes associated with functional pancreatic NET (PNET) can be effectively treated with somatostatin analogs. On the other hand, the efficacy of systemic chemotherapy for these patients is limited. A placebo-controlled, double-blind, prospective, and randomized study showed that octreotide LAR improves progression-free survival in patients with advanced midgut functional "carcinoids." In patients with advanced pancreatic NET, randomized, placebo-controlled studies have recently demonstrated that treatment with the tyrosine kinase inhibitor sunitinib or with mTOR inhibitor everolimus is associated with improved progression-free survival. Based on these studies, octreotide LAR, sunitinib, or everolimus are now considered as first-line therapeutic options in patients with advanced NET. Future studies will likely further define the role of these agents in patients with carcinoid liver metastasis and pancreatic NET liver metastasis.

New treatment strategies in advanced neuroendocrine tumours

Malignant well-differentiated neuroendocrine tumours of the pancreas and the gastrointestinal tract are rare and clinically challenging heterogeneous neoplasms. This review focuses on neuroendocrine tumours grade 1 and grade 2 (new WHO classification 2010), in comparison to the neuroendocrine tumours grade 3 group, corresponding to poorly differentiated neuroendocrine carcinomas. Surgical resection of the primary and metastases remains the only curative treatment, however many patients with neuroendocrine tumours are diagnosed once unresectable metastases have occurred; management of functioning syndromes with somatostatin analogues remains the priority. Pasireotide, a new somatostatin analogue, is currently undergoing evaluation for carcinoid syndrome. Treatment options for advanced neuroendocrine tumours differ from pancreatic gastrointestinal tract neuroendocrine tumours: (a) in pancreatic neuroendocrine tumours, streptozotocin-based chemotherapies are challenged by other cytotoxic agents (dacarbazine, temozolomide and oxaliplatin); two randomized, placebo-controlled phase III studies have demonstrated that everolimus and sunitinib significantly improved progression-free-survival; (b) in midgut neuroendocrine tumours, octreotide improved time-to-progression in patients with a low proliferation index and low liver burden; preliminary data suggesting efficacy of bevacizumab are still to be confirmed; the effect of everolimus associated with octreotide was almost significant on progression-free-survival in a phase III trial. Liver-directed therapies are effective in both tumour types. New techniques of embolization need further evaluation and must be formally compared to other therapies. Finally, peptide receptor radionuclide therapy has shown promising activity in non-comparative studies in advanced neuroendocrine tumours.

Contemporary management of nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND

This article reviews the current literature and recommendations pertaining to the management of nonfunctioning pancreatic neuroendocrine tumors.

DISCUSSION

In recent years the detection of nonfunctioning pancreatic neuroendocrine tumors has increased coincident with the increased use of cross-sectional imaging and is now thought to represent 2-10% of all pancreatic tumors. Improved understanding of the biology and behavior of these heterogeneous tumors is needed to guide therapy. The present review discusses diagnostics, therapeutics including emerging molecular analytics, and surveillance recommendations.

Gastroenteropancreatic neuroendocrine tumors: new insights in the diagnosis and therapy

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are relatively rare and heterogenous malignancies. Recent advances in histopathological classification according to the anatomical site of origin, proliferation rate, and extend of the disease have created a valid and powerful tool for the prognostic stratification of GEP-NETs. Chromogranin A is still the best available marker used for the biochemical confirmation of these tumors, but new more sensitive markers are urgently required. Although scintigraphy with (111)In-octreotide has widely been applied for the localization and staging of GEP-NETs, newer imaging modalities based on the functional characteristics of these tumors are evolving aiming not only to facilitate the diagnosis but also prognosis and evaluation of treatment. Somatostatin receptors are the primary therapeutic targets through somatostatin analogs and peptide receptor radionuclide therapy (PRRT) producing symptomatic, biochemical and to a lesser extent antiproliferative effects. Due to the relatively limited and erratic response to chemotherapy, new molecular targeted therapies exploiting some of the biological properties of GEP-NETs such as increased vascularity and inhibition of pathways involved in downstream signal transduction have evolved. Some of these therapies, the mTOR inhibitor everolimus and the tyrosine kinase inhibitor sunitinib, have been recently validated in phase III studies producing practice changing outcomes. In addition, two oral chemotherapeutic agents temozolomide and capecitabine, show promising effects and may replace streptozotocin-based regimens whereas combination therapies with the angiogenesis inhibitor bevacizumab are being investigated. Although progression free survival is used as a feasible primary end point due to the long survival of patients even in the presence of extensive disease prolongation of overall survival following the introduction of new therapies needs to be established.

Radioembolization for primary and metastatic liver cancer

The incidence of hepatocellular carcinoma is increasing. Most patients present beyond potentially curative options and are usually affected by underlying cirrhosis. In this scenario, transarterial therapies, such as radioembolization, are rapidly gaining acceptance as a potential therapy for hepatocellular carcinoma and liver metastases. Radioembolization is a catheter-based liver-directed therapy that involves the injection of micron-sized embolic particles loaded with a radioisotope by use of percutaneous transarterial techniques. Cancer cells are preferentially supplied by arterial blood and normal hepatocytes by portal venous blood; therefore, radioembolization specifically targets tumor cells with a high dose of lethal radiation and spares healthy hepatocytes. The antitumor effect mostly comes from radiation rather than embolization. The most commonly used radioisotope is yttrium-90. The commercially available devices are TheraSphere (glass based; MDS Nordion, Ottawa, Canada) and SIR-Sphere (resin based; Sirtex, Lane Cove, Australia). The procedure is performed on an outpatient basis. The incidence of complications is comparatively less than other locoregional therapies and may include nausea, fatigue, abdominal pain, hepatic dysfunction, biliary injury, fibrosis, radiation pneumonitis, gastrointestinal ulcers, and vascular injury. However, these complications can be avoided by meticulous pretreatment assessment, careful patient selection, and adequate dosimetry. This article focuses on both the technical and clinical aspects of radioembolization with emphasis on patient selection, uses and complications.

Pancreatic endocrine tumors in multiple endocrine neoplasia type 1 syndrome: review of literature

OBJECTIVE

To analyze the surgical approach to multiple endocrine neoplasia type 1 (MEN 1)-related pancreatic endocrine tumors (PETs).

METHODS

We reviewed selected publications and our personal experience with MEN 1-associated PETs to delineate their general characteristics, current practice and controversies, preoperative imaging and intraoperative assessment, and appropriate therapeutic strategies including radical surgical procedures.

RESULTS

The penetrance of PETs in the setting of MEN 1 is similar to that of parathyroid tumors, even though hyperparathyroidism is usually the first manifestation of MEN 1 syndrome. In contrast with the sporadic counterparts, MEN 1-related PETs are characterized by an early onset, multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histologic type and the size of these tumors correlate with malignant potential.

CONCLUSION

The rationale for surgical considerations for these tumors is to curtail the malignant progression of the disease and to cure or aid in management of the associated biochemical syndromes. A surgical procedure is often the treatment of choice for PETs in patients with MEN 1. Monitoring of pancreatic peptides and use of diagnostic imaging allow an early pancreatic resection, in conjunction with prevention of metastatic PETs and improvement of long-term survival. Hepatic metastatic lesions can be successfully treated by surgical resection.

Novel medical therapies of recurrent and metastatic gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors (NETs) of the gastrointestinal tract and pancreas are slow-growing but commonly advanced malignancies with increasing incidence and prevalence. While locoregional disease can be effectively managed with resection, treatment of recurrent, progressive or metastatic disease has until recently been limited to palliative embolization and cytoreducitve surgery, with cytotoxic chemotherapeutic agents being the last resort. However, novel molecular targeted therapies inhibiting malignant cell proliferation and neoangiogenesis, as well as new cytotoxic chemotherapy drugs and somatostatin analogues, are all being investigated for their potential use in advanced neuroendocrine tumors. Long-acting release forms of octreotide have been shown to not only improve symptoms in carcinoid syndrome but to also delay progression of gastrointestinal NETs. On the other hand, phase III trials have demonstrated everolimus (with octreotide) and sunitinib to increase progression-free survival in pancreatic NETs. Use of bevacizumab has also shown promise in a phase II study, and results of an ongoing phase III trial comparing it to interferon are eagerly expected. Use of radiolabeled somatostatin analogues is still under investigation, though several phase II studies are encouraging. New cytotoxic agents, most notably temozolomide and capecitabine, are already in use, but their relative effectiveness compared to streptozocin in pancreatic NETs is yet to be determined.

A multimodal approach to the management of neuroendocrine tumour liver metastases

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

Treatment of neuroendocrine tumor liver metastases

In the care of patients with hepatic neuroendocrine metastases, medical oncologists should work in multidisciplinary fashion with surgeons, interventional radiologists, and radiation oncologists to assess the potential utility of liver-directed and systemic therapies. This paper addresses the various roles and evidence basis for cytoreductive surgery, thermal ablation (radiofrequency, microwave, and cryoablation), and embolization (bland embolization (HAE), chemoembolization (HACE), and radioembolization) as liver-directed therapies. Somatostatin analogues, cytotoxic chemotherapy, and the newer agents everolimus and suntinib are discussed as a means for controlling intra- and extrahepatic disease, along with peptide receptor radiotherapy (PRRT). Finally, the experience with orthotopic liver transplant for neuroendocrine tumors is described.

Predictors of response to radio-embolization (TheraSphere®) treatment of neuroendocrine liver metastasis

BACKGROUND

Neuroendocrine tumours (NET) frequently metastasize to the liver. NET liver metastasis has been shown to respond to Yttrium-90 microspheres therapy. The aims of the present study were to define factors that predict the response to radio-embolization in patients with NET liver metastases.

METHODS

From January 2006 until March 2009, all patients with NET liver metastasis that received radio-embolization using TheraSphere® (glass microspheres) were reviewed. The response was determined by a change in the percentage of necrosis (ΔN%) after the first radio-embolization based on the modified RECIST criteria (mRECIST) criteria. The following confounding variables were measured: age, gender, size of the lesions, liver involvement, World Health Organization (WHO) classification, the presence of extra-hepatic metastasis, octereotide treatment and previous operative [surgery and (RFA)] and non-operative treatments (chemo-embolization and bland-embolization).

RESULTS

In all, 25 patients were identified, with a median follow-up of 21.7 months. The median age was 64.6 years, 28% had extra-hepatic metastasis and 56% were WHO stage 2. Post-treatment, the mean ΔN% was 48.4%. Previous surgical therapy was a significant predictor of the response with a response rate of 66.7 ΔN% vs. 31.5 ΔN% (P= 0.02). Bilateral liver disease, a high percentage of liver involvement and large metastatic lesions were inversely related to the degree of tumour response although did not reach statistical significance.

CONCLUSION

Radio-embolization increased the necrosis of NET liver metastasis mainly in patients with less bulky disease. This may imply that surgical therapy before radio-embolization would increase the response rates.

Radioembolization for neuroendocrine liver metastases: safety, imaging, and long-term outcomes

PURPOSE

To present long-term outcomes on the safety and efficacy of Yttrium-90 radioembolization in the treatment of unresectable hepatic neuroendocrine metastases refractory to standard-of-care therapy.

METHODS AND MATERIALS

This study was approved by our institutional review board and was compliant with the Health Insurance Portability and Accountability Act. Forty patients with hepatic neuroendocrine metastases were treated with (90)Y radioembolization at a single center. Toxicity was assessed using National Cancer Institute Common Terminology Criteria v3.0. Response to therapy was assessed by World Health Organization (WHO) guidelines for size and European Association for the Study of the Liver disease (EASL) guidelines for necrosis. Time to response and overall survival were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed.

RESULTS

The median dose was 113 Gy (29-299 Gy). Clinical toxicities included fatigue (63%), nausea/vomiting (40%), abdominal pain (18%), fever (8%), diarrhea and weight loss (5%); Grade 3 and 4 bilirubin toxicities were experienced by 2 patients and 1 patient, respectively. Different responses were noted by WHO (complete response, 1.2%; partial response, 62.7%) and EASL (complete response, 20.5%; partial response, 43.4%). Median time to response was 4 and 4.9 months by lesion and patient, respectively. The 1-, 2-, and 3-year overall survival rates were 72.5%, 62.5%, and 45%, respectively. Eastern Cooperative Oncology Group (ECOG) performance score 0 (p < 0.0001), tumor burden ≤25% (p = 0.0019), albumin ≥3.5 g/dL (p = 0.017), and bilirubin ≤1.2 mg/dL (p = 0.002) prognosticated survival on univariate analysis; only ECOG performance score 0 and bilirubin ≤1.2 mg/dL prognosticated better survival outcome on multivariate analysis (p = 0.0001 and p = 0.02).

CONCLUSION

Yttrium-90 therapy for hepatic neuroendocrine metastases leads to satisfactory tumor response and patient survival with low toxicity, in line with published national guidelines recommending radioembolization as a potential option for unresectable hepatic neuroendocrine metastases.

Consensus recommendations for the diagnosis and management of well-differentiated gastroenterohepatic neuroendocrine tumours: a revised statement from a Canadian National Expert Group

Well-differentiated neuroendocrine tumours (nets-previously called "carcinoid tumours") are relatively rare tumours originating from the diffuse neuroendocrine system; they are found most often in the bronchial or gastrointestinal systems. In Canada, gastroenterohepatic NETS represent less than 0.25% of oncology cases. Because of the relative rarity of these tumours, diagnostic and therapeutic approaches vary and are often based on individual physician experience. A number of European and North American groups have developed consensus guidelines for the diagnosis and management of well-differentiated gastroenterohepatic NETS, and in 2006, Canadian consensus guidelines were published by a Canadian expert group. The updated and expanded current Canadian guidelines are based on a consensus meeting held in Paris, France, in 2008 and are based on the most current literature.

Liver-directed therapy for neuroendocrine neoplasm hepatic metastasis prolongs survival following progression after initial surgery

BACKGROUND

Surgery confers the best chance of long-term survival in patients with neuroendocrine neoplasm hepatic metastases (NENHM). Disease progression invariably occurs in the majority of patients. No previous study has addressed the outcomes after treatment of hepatic disease progression in patients who initially underwent surgical extirpation of NENHM. This was the principal aim of the current study.

METHODS

Seventy-four patients with NENHM underwent surgery for NENHM between December 1992 and December 2009. Of these, 50 patients developed disease progression in the liver. These patients were then treated with specific liver-directed therapies according to consensus of a multidisciplinary team. The current study evaluates progression-free survival (PFS) and overall survival (OS) following treatment of hepatic disease progression with specific liver-directed therapies.

RESULTS

No patient was lost to follow up. The median follow-up after treatment of progression was 29 months (range = 2-137). The median PFS and OS after diagnosis of disease progression were 15 and 48 months, respectively. Specific liver-directed therapies included surgery in 10 patients, radioembolization in 15, cytotoxic chemotherapy in 14, and conservative therapy in 11. Four independent factors associated with PFS and OS were identified through a multivariate analysis. These were initial progression-free survival (PFS, P = 0.006, HR= 0.32), extra-hepatic disease (OS, P = 0.029, HR = 4.04; PFS, P = 0.004, HR = 4.03), histological grade (PFS, P = 0.006, HR = 4.08), and type of secondary intervention (PFS, P = 0.024, HR = 0.63).

CONCLUSION

A multimodality approach towards treatment of disease progression as shown in this study that includes repeat surgery or radioembolization has been shown to achieve a superior outcome in the setting of disease progression/recurrence.

Targeted radionuclide therapy

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Role of everolimus in pancreatic neuroendocrine tumors

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

New treatment options for patients with advanced neuroendocrine tumors

Well- to moderately differentiated neuroendocrine tumors (NET) are a heterogeneous group of malignancies for which a range of therapeutic options have been employed. For patients with localized NET, surgical resection remains the mainstay of treatment. Surgical resection of hepatic metastases or hepatic artery embolization may also be beneficial in patients with hepatic-predominant metastatic disease. Symptoms of hormonal excess, such as carcinoid syndrome and syndromes associated with functional pancreatic NET, can be effectively treated with somatostatin analogs. Systemic treatment options for patients with advanced NET have been limited. Treatment with the somatostatin analog octreotide has been shown to improve progression-free survival in patients with advanced midgut carcinoid tumors, and the potential antiproliferative effect of somatostatin analogs in patients with other NET subtypes is currently under investigation. Patients with advanced pancreatic NET may also respond to treatment with streptozocin or temozolomide-based therapy. In patients with advanced pancreatic NET, randomized, placebo-controlled studies have recently demonstrated that treatment with the tyrosine kinase inhibitor sunitinib or with the mTOR inhibitor everolimus is associated with improved progression-free survival. Based on these studies, sunitinib or everolimus should now be considered as therapeutic options in patients with advanced pancreatic NET. Initial phase II studies have also suggested activity associated with VEGF pathway and mTOR inhibitors in patients with advanced carcinoid tumors. Future studies will likely further define the role of these agents in the advanced carcinoid patient population.

Radioembolization of symptomatic, unresectable neuroendocrine hepatic metastases using yttrium-90 microspheres

PURPOSE

To evaluate safety, efficacy, and symptom-control of radioembolization in patients with unresectable liver metastases from neuroendocrine tumors (NETLMs).

MATERIALS AND METHODS

Forty-two patients (mean age of 62 years) with treatment-refractory NETLMs underwent radioembolization using yttrium-90 ((90)Y) resin microspheres. Posttreatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST) and tumor-marker levels. Laboratory and clinical toxicities and clinical symptoms were monitored.

RESULTS

The median activity delivered was 1.63 GBq (range 0.63-2.36). Imaging follow-up using RECIST at 3-month follow-up demonstrated partial response, stable disease, and progressive disease in 22.5, 75.0, and 2.5% of patients, respectively. In 97.5% of patients, the liver lesions appeared hypovascular or partially necrotic. The mean follow-up was 16.2 months with 40 patients (95.2%) remaining alive. The median decrease in tumor-marker levels at 3 months was 54.8% (chromogranin A) and 37.3% (serotonin), respectively. There were no acute or delayed toxicities greater than grade 2 according to Common Terminology Criteria for Adverse Events [CTCAE (v3.0)]. No radiation-induced liver disease was noted. Improvement of clinical symptoms 3 months after treatment was observed in 36 of 38 symptomatic patients.

CONCLUSION

Radioembolization with (90)Y-microspheres is a safe and effective treatment option in patients with otherwise treatment-refractory NETLMs. Antitumoral effect is supported by good local tumor control, decreased tumor-marker levels, and improved clinical symptoms. Further investigation is warranted to define the role of radioembolization in the treatment paradigm for NETLMs.

Neuroendocrine tumors of the gynecologic tract: A Society of Gynecologic Oncology (SGO) clinical document

OBJECTIVE

Neuroendocrine tumors of the gynecologic tract are rare, and pose a significant clinical challenge because of the tumor heterogeneity and lack of standardized guidelines for treatment. This manuscript summarizes the available literature concerning these tumors in an effort to provide the clinician a framework from which to guide patient management.

METHODS

MEDLINE was searched for all research articles published in English between January 1, 1966 and March 1, 2011 in which the studied population included women diagnosed with neuroendocrine tumors of the gynecologic tract. Although preference was given to prospective studies, studies were not limited by design or by numbers of subjects given the limited availability of reports.

RESULTS

Most, but not all, neuroendocrine tumors of the gynecologic tract have an aggressive clinical course and those of the cervix histologically and clinically share similarities with small cell lung cancer. Cumulative data supports a multi-modality therapeutic strategy. A proposed management algorithm for neuroendocrine carcinomas of the cervix is outlined. For less frequent disease sites including the adnexa, uterus, vagina and vulva, as well as well differentiated carcinoid tumors, surgical resection is appropriate in selected cases. Etoposide/platinum based chemotherapy is used for neuroendocrine carcinomas but not for well differentiated carcinoid tumors. Well differentiated carcinoid and atypical carcinoid tumors should be managed similar to gastroenteropancreatic NETs (GEP-NETs).

CONCLUSIONS

Most neuroendocrine tumors of the gynecologic tract require a multi-modality therapeutic approach, determined by extent of disease and primary organ of involvement. Pathologic diagnosis is critical to guide therapy.

General selection criteria of patients for radioembolization of liver tumors: an international working group report

A combined treatment approach that incorporates surgical resection, ablation, chemotherapy, targeted agents, and radiotherapy has augmented the management of liver tumors (both primary and metastatic). The challenge that remains is how to reduce the burden of liver disease and thus enable greater patient eligibility for resection as well as lengthened survival for those who remain unsuitable for surgery. Radioembolization can deliver high doses of radiation preferentially to liver tumors and is a valuable treatment option that should be considered as part of a multimodal treatment approach for the management of patients in whom the liver is the sole or dominant site of disease. Essential in this consideration is a careful assessment by a multidisciplinary team of the individuals most likely to benefit from this treatment modality. Along with the clinical benefits, integration of radioembolization into the treatment paradigm can provide added options of using systemic chemotherapy synergistically as a radiosensitizer and to control extrahepatic metastases, permitting a reduction in hepatic disease and conserving remaining liver function. If successful, the possibility of improved patient survival and quality of life is increased.

Transarterial chemoembolization and selective internal radiation for the treatment of patients with metastatic neuroendocrine tumors: a comparison of efficacy and cost

BACKGROUND

Hepatic arterial therapy (HAT) has been proven to be effective at palliation of hormonal symptoms of metastatic neuroendocrine tumors (NETs), as well as a means of cytoreduction. Recently, the newer modalities of yttrium-90 and drug-eluting beads with doxorubicin (DEBDOX) have been reported to be effective in the treatment of metastatic NETs. The aim of this study was to compare the safety, efficacy, and cost of selective internal radiation with DEB therapy.

METHODS

An institutional review board-approved, multicenter, multinational prospective treatment registry to investigate the safety and efficacy of yttrium-90 and doxorubicin microspheres was reviewed.

RESULTS

In all, 43 patients underwent a combined 69 HAT treatments, with 15 patients receiving 23 yttrium-90 treatments and 28 patients receiving 46 DEBDOX treatments. The extent of disease-based on the number of lesions, bilobar distribution, patient performance status, and size of largest lesion-was similar in both the yttrium-90 and DEBDOX groups. After a median follow-up of 12 months, response rates were similar with the two treatments, but then there was a significantly lower response rate in the yttrium-90 group at 12 months than in the DEBDOX group. In an evaluation of cost for the two treatments, the median cost for yttrium-90 was $25,243 and the median cost for DEBDOX was $13,400.

CONCLUSION

HAT is a safe and effective therapy in patients with unresectable NETs to the liver. The size of the lesions, total lesion volume, and expense of therapy need to be considered when choosing which HAT method is optimal.

Yttrium-90 (90Y) in the principal radionuclide therapies: an efficacy correlation between peptide receptor radionuclide therapy, radioimmunotherapy and transarterial radioembolization therapy. Ten years of experience (1999-2009)

The clinical application of the pure beta emitter (90)Y constitutes a fundamental advancement in non-invasive medicine. Nowadays, mainly three oncological therapies exploit the intrinsic emissive characteristic of (90)Y. Radionuclide therapies include peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumour (NET) treatment, radioimmunotherapy (RIT) in non-Hodgkin's lymphoma (NHL) treatment and transarterial radioembolization therapy (TARET) in unresectable hepatocellular carcinoma (HCC) and liver metastatic colorectal cancer (mCRC) treatment. The last ten years of clinical experience from E-PubMed research have been reviewed and an efficacy correlation between (90)Y-therapies has shown a better objective response rate for RIT (ORR 80±15%; range 53-100) compared to PRRT (ORR 23.5±14%; range 9-50), and TARET (ORR for mCRC, 40±25%; range 19-91, and ORR for HCC, 42±20%; range 20-82). This review reports on the state of the art of the efficacy of (90)Y-therapies from the last decade and discusses new perspectives of therapeutic development.

Future directions in the treatment of neuroendocrine tumors: consensus report of the National Cancer Institute Neuroendocrine Tumor clinical trials planning meeting

Neuroendocrine tumors (NETs) arise from a variety of anatomic sites and share the capacity for production of hormones and vasoactive peptides. Because of their perceived rarity, NETs have not historically been a focus of rigorous clinical research. However, the diagnosed incidence of NETs has been increasing, and the estimated prevalence in the United States exceeds 100,000 individuals. The recent completion of several phase III studies, including those evaluating octreotide, sunitinib, and everolimus, has demonstrated that rigorous evaluation of novel agents in this disease is both feasible and can lead to practice-changing outcomes. The NET Task Force of the National Cancer Institute GI Steering Committee convened a clinical trials planning meeting to identify key unmet needs, develop appropriate study end points, standardize clinical trial inclusion criteria, and formulate priorities for future NET studies for the US cooperative group program. Emphasis was placed on the development of well-designed clinical trials with clearly defined efficacy criteria. Key recommendations include the evaluation of pancreatic NET separately from NETs of other sites and the exclusion of patients with poorly differentiated histologies from trials focused on low-grade histologies. Studies evaluating novel agents for the control of hormonal syndromes should avoid somatostatin analog washout periods when possible and should include quality-of-life end points. Because of the observed long survival after progression of many patients, progression-free survival is recommended as a feasible and relevant primary end point for both phase III studies and phase II studies where a delay in progression is expected in the absence of radiologic responses.

Recent progress in the understanding, diagnosis, and treatment of gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are relatively rare tumors that arise from the diffuse neuroendocrine system. This heterogeneous group of tumors was often considered a single entity. This belied their biological diversity, and the biggest advance in understanding these tumors over the past decades has been in understanding this diversity. Diagnosis of these tumors has been aided by advances in pathological diagnosis and classification and tumor imaging with endoscopic ultrasound and somatostatin receptor fusion imaging. Genetic and molecular advances have identified molecular targets in the treatment of these tumors. Surgery remains the mainstay of treatment, amply supported by interventional radiological techniques, including embolization. Treatment of metastatic disease has improved significantly with the addition of several new agents, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and yttrium-90-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and lutetium-177-DOTA octreotate. Despite significant advances in the understanding and management of GEP-NETs, the survival of patients remains largely unchanged and there remains a need for the development of national and international research collaborations to spearhead future efforts.

Pancreatic endocrine tumors

Pancreatic endocrine tumors have been steadily growing in incidence and prevalence during the last two decades, showing an incidence of 4-5/1,000,000 population. They represent a heterogeneous group with very varying tumor biology and prognosis. About half of the patients present clinical symptoms and syndromes related to substances released from the tumors (Zollinger-Ellison syndrome, insulinoma, glucagonoma, etc) and the other half are so-called nonfunctioning tumors mainly presenting with symptoms such as obstruction, jaundice, bleeding, and abdominal mass. Ten percent to 15% of the pancreatic endocrine tumors are part of an inherited syndrome such as multiple endocrine neoplasia type 1 (MEN-1), von Hippel-Lindau (VHL), neurofibromatosis, or tuberousclerosis. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, and glucagon. Moreover, the biochemical diagnosis includes measurement of chromogranins A and B or specific hormones such as gastrin, insulin, glucagon, and vasoactive intestinal polypeptide (VIP) in the circulation. In addition to standard localization procedures, radiology (computed tomography [CT] scan, magnetic resonance imaging [MRI], ultrasound [US]), somatostatin receptor scintigraphy, and most recently positron emission tomography with specific isotopes such as (11)C-5 hydroxytryptamin ((11)C-5-HTP), fluorodopa and (68)Ga-1,4,7,10-tetra-azacyclododecane-N,N',N″,N‴-tetra-acetic acid (DOTA)-octreotate are performed. Surgery is still one of the cornerstones in the management of pancreatic endocrine tumors, but curative surgery is rarely obtained in most cases because of metastatic disease. Debulking and other cytoreductive procedures might facilitate systemic treatment. Cytotoxic drugs, biological agents, such as somatostatin analogs, alpha interferons, mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors are routinely used. Tumor-targeted radioactive treatment is available in many centres in Europe and is effective in patients with tumors that express high content of somatostatin receptors type 2 and 5. In the future, treatment will be based on tumor biology and molecular genetics with the aim of so-called personalized medicine.

Selective internal radiation therapy for gastrointestinal neuroendocrine tumour liver metastases: a new and effective modality for treatment

Background. Nonresectable neuroendocrine tumour (NET) liver metastases respond poorly to most widely available and used therapies. Selective Internal Radiation Therapy (SIRT) is becoming recognized as a new modality for selectively treating non-resectable liver tumours. This paper presents an experience of 14 patients with non-resectable NET liver metastases treated with SIRT. Methods. Between September 1997 and October 2009 14 patients with extensive NET liver metastases were treated with 2.0 to 3.0 GBq of (90)Yttrium microspheres. Repeat SIRT was undertaken in three patients after 16, 27, and 48 months, respectively. Responses were assessed clinically, biochemically, and with serial CT scans. Survival was measured from initial SIRT. Results. Some response was seen in all 14 patients. Carcinoid syndrome improved or resolved in 10/10 instances. 24-hour urinary 5-HIAA or serum chromogranin A levels fell dramatically in 5/7 patients following SIRT. Serial CT scans revealed partial response or stable disease in all 14 patients. Repeat treatment in three patients experiencing progression was associated with a further response. Median survival after SIRT is 25 months with 6 patients being alive (and 3 patients still asymptomatic), at 19, 22, 23, 23, 58, and 60 months. Conclusions. SIRT is an effective and well-tolerated treatment for non-resectable NET liver metastases capable of both alleviating the carcinoid syndrome and achieving significant tumour regression. Repeat treatment is an option and liver resection after downstaging may also become possible.

Multimodal liver-directed management of neuroendocrine hepatic metastases

A preponderance of patients with neuroendocrine tumors (NETs) will experience hepatic metastases during the course of their disease. Many diagnoses of NETs are made only after the neoplasms have spread from their primary gastroenteropancreatic sites to the liver. This paper reviews current evidence-based treatments for neuroendocrine hepatic metastases, encompassing surgery, hepatic artery embolization (HAE) and chemoembolization (HACE), radioembolization, hepatic artery infusion (HAI), thermal ablation (radiofrequency, microwave, and cryoablation), alcohol ablation, and liver transplantation as therapeutic modalities. Consideration of a multidisciplinary approach to liver-directed therapy is strongly encouraged to limit morbidity and mortality in this patient population.

Radioembolization in the treatment of neuroendocrine tumor metastases to the liver

Surgical excision remains the preferred treatment for resectable hepatic metastases of neuroendocrine tumors. In cases of more disseminated hepatic disease, transarterial radioembolization with Yttrium-90- (90Y-) labeled microspheres has been demonstrated as a viable option for symptom and locoregional tumor control. On an outpatient basis, radioembolization can be utilized from early line to salvage phases, in various combinations with systemic therapies. Review of available data shows encouraging safety and efficacy profiles for the intraarterial application of 90Y for the treatment of mNETs of the liver. Symptom control and decrease in somatostatin analog use can be achieved, as well as prolonged survival.

Selective intraarterial radionuclide therapy with yttrium-90 (Y-90) microspheres for hepatic neuroendocrine metastases: Initial experience at a single center

Background/Aim. Selective intraarterial radionuclide therapy (SIRT) with Yttrium-90 (Y-90) microspheres is also known as radioembolization and delivers high doses of radiation to hepatic tumors with minimum healthy liver exposure. The aim of this study was to present our preliminary experience in the role of liver directed radiotherapy with Y-90 microspheres for the treatment of unresectable hepatic metastases from neuroendocrine tumors (NET). Methods. The results of SIRT in 10 patients (5 males, 5 females; mean age 48.7 years; age range 24-73 years) with metastatic liver disease from NETs during the period from April 2008 through August 2010 were reviewed. All patients had meticulous pre- and post-imaging studies as a part of their work-up procedure, as well as serologic tests of liver function to determine the extent of liver function damage. The patients who were eligible for SIRT had pretreatment visceral angiography to define and occlude non-target arteries. Results. The mean ? SD administered SIR-Spheres? activity was 1.49 ? 0.42 GBq (range 0.72-2.21 GBq) in all the patients. These treatments delivered a dose of 99.73 ? 66.36 Gy (range 49- 420.8 Gy) to the target tumors. The estimated dose to the lungs and normal liver was 4.45 ? 1.95 Gy (range 2.4-8.5 Gy) and 26.73 ? 14.19 Gy (range 5-58.9 Gy), respectively. Overall response rate of 90% and patient tolerance was satisfactory for most patients. Conclusion. From our limited experience, we can conclude that SIRT with Y-90 microspheres is a safe and efficacious treatment option for patients with liver metastasis of NET without any serious side effects.

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

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

Well-differentiated neuroendocrine tumors: a review covering basic principles to loco-regional and targeted therapies

Neuroendocrine tumors (NETs) are a complex group of malignancies with variable prognosis and response to treatment. For pancreatic neuroendocrine and carcinoid tumors, traditional cytotoxic chemotherapies have demonstrated minimal activity. Current approaches for treatment of metastatic disease use a combination of loco-regional and targeted biological therapies. Clinical trials remain critical for evaluation of new and promising therapeutic options for patients with NETs.