A fuller understanding of pancreatic neuroendocrine tumours combined with aggressive management improves outcome

The Clinicopathological Characteristics and Surgical Treatment of Gastrointestinal Neuroendocrine Neoplasm-A 10-Year Single-Center Experience

Background: Gastrointestinal neuroendocrine neoplasms (GI-NENs) represent a diverse group of tumors, with surgical resection being the gold standard for treatment. Materials and Methods: A retrospective analysis was conducted on 63 patients (32 women, 31 men) who underwent surgery for GI-NENs at the Department of Digestive Tract Surgery from January 2013 to June 2023. Tumors were classified by stage (localized, regionally advanced, metastatic). Results: Clinical symptoms were reported by 42 (66.7%) patients, with abdominal pain being the most common symptom, affecting 28 (44.4%) patients. The majority of tumors (44, 69.8%) originated in the midgut. The most frequently performed surgery was right hemicolectomy, carried out on 33 (52.4%) patients. Radical tumor resection was performed in 35 (55.6%) patients. Postoperative complications occurred in 12 (19%) patients, with male gender identified as an independent predictive factor for complications (p = 0.04). Non-functioning tumors were more common (33, 52.4%), and most tumors were classified as grade 1 histopathologically (49, 77.8%). Distant metastases were present in 29 (46%) patients. The overall two-year survival rate was 94.9%, with a five-year survival rate also estimated at 94.9%. Conclusions: GI-NENs are often diagnosed at advanced stages, frequently with distant or lymph node metastases, and predominantly arise in the midgut. Despite low postoperative morbidity and mortality, male gender may be a predictor of postoperative complications. Overall, the prognosis for GI-NENs is favorable, reflected in high overall survival rates.

Endoscopic ultrasound-guided fine-needle aspiration vs fine-needle biopsy for the diagnosis of pancreatic neuroendocrine tumors

Background and study aims  Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) as a method of obtaining preoperative diagnosis of pancreatic neuroendocrine tumors (PanNETs) has been reported in several series. Fine-needle biopsies (FNB) are increasingly employed to obtain core specimens during EUS. However, the differences in efficacy between these sampling methods in the diagnosis of PanNETs still needs to be defined. Patients and methods  Over a 13-year period, all patients who underwent EUS-guided tissue sampling of suspicious pancreatic lesions with clinical, endoscopic and pathologic details were entered into an electronic database. Lesions underwent EUS-FNA or FNB sampling, or a combination of the two. The accuracy and safety of different EUS-guided sampling methods for confirmed PanNETs were investigated. Results  A total of 91 patients (M/F: 42/49, median age: 57 years), who underwent 102 EUS procedures had a final diagnosis of PanNET. Both EUS-guided sampling modalities were used in 28 procedures, EUS-FNA alone was used in 61 cases, while EUS-FNB alone in 13 cases. Diagnostic yield of EUS-FNA and EUS-FNB alone, including the inadequate specimens, was 77.5 % (95 %CI: 68.9 - 86.2 %) and 85.4 % (95 %CI: 74.6 - 96.2 %), respectively. The combination of both sampling modalities established the diagnosis in 96.4 % of cases (27/28) (95 %CI: 89.6 - 100 %), significantly superior to EUS-FNA alone ( P  = 0.023). Diagnostic sensitivity among the adequate samples for EUS-FNA, EUS-FNB and for the combination of the two methods was 88.4 % (95 %CI: 80.9 - 96.0 %), 94.3 % (95 %CI: 86.6 - 100 %) and 100 % (95 %CI: 100 - 100 %). There was one reported complication, a post-FNA bleeding, treated conservatively. Conclusions  EUS-FNB improves diagnostic sensitivity and confers additional information to cytological assessment of PanNETs.

Prognostic Validity of the American Joint Committee on Cancer Eighth Edition TNM Staging System for Surgically Treated and Well-Differentiated Pancreatic Neuroendocrine Tumors: A Comprehensive Analysis of 254 Consecutive Patients From a Large Chinese Institution

OBJECTIVES

We aimed to validate the novel American Joint Committee on Cancer (AJCC) eighth edition staging manual for well-differentiated (G1/G2) pancreatic neuroendocrine tumors (pNETs).

METHODS

Data of eligible patients were retrospectively collected, grouped, and analyzed by applying the new AJCC system.

RESULTS

According to the AJCC eighth staging manual for pNETs, 93, 66, 53, and 42 patients had stage I, II, III, and IV disease, respectively, with estimated 5-year overall survival (OS) rates of 96.9%, 92.8%, 48.4%, and 16.8% (P < 0.005), respectively. A total of 57, 28, 20, and 17 patients with G1 pNETs and 36, 38, 33, and 25 ones with G2 tumors were defined by the new AJCC system as having stage I, II, III, and IV disease, respectively. The estimated 5-year OS for stage I, II, III and IV disease was 100.0%, 97.1%, 52.5%, and 18.2%, respectively, for G1 pNETs (P < 0.005) and 94.2%, 90.3%, 38.7%, and 12.7%, respectively, for G2 tumors (P < 0.005). The novel AJCC classification, tumor grading, and radical resection were all prognostic predictors for OS in patients with pNETs.

CONCLUSIONS

The new AJCC eighth staging system for well-differentiated pNETs was prognostic and might be adopted in clinical practice.

Economics of gastroenteropancreatic neuroendocrine tumors: a systematic review

BACKGROUND

Despite current interest, enthusiasm and progress in the development of therapies for gastroenteropancreatic (GEP) neuroendocrine tumors (NETs), there are substantial gaps in the published literature regarding cost-of-illness analyses, economic evaluation and budget impact analyses. Compounding the issue is that data on resource utilization and cost-effectiveness of different diagnostic and therapeutic modalities for GEP-NETs are scarce.

METHODS

A systematic review on the economic impact of GEP-NETs was carried out using four databases: EMBASE, PubMed, the National Health Service Economic Evaluation Database and Cochrane review. Fully published articles from January 2000 to May 2017, in English and Spanish, were included. All articles that satisfied the inclusion criteria were included in the systematic review; summary descriptive statistics were used to describe the methodological characteristics.

RESULTS

The 14 studies selected included cost-of-illness analyses (n = 4), economic evaluations (n = 7) and budget impact analyses (n = 3). Almost all studies were performed in the United States. Healthcare costs for patients with NETs included medication, outpatient visits, hospitalizations, and check-ups/tests. Reducing adverse events is an area where cost savings could be achieved; however, there was not enough evidence on the cost impact of adverse events.

CONCLUSION

There is a lack of data related to resource utilization in the field of GEP-NETs. Therefore, cost-effectiveness and budget impact studies of existing and emerging treatments are urgently needed to help the decision-making process for patients with NETs.

Clinical outcome and long-term survival of 150 consecutive patients with pancreatic neuroendocrine tumors: A comprehensive analysis by the World Health Organization 2010 grading classification

BACKGROUND AND OBJECTIVE

The World Health Organization (WHO) has revised its grading system for pancreatic neuroendocrine tumors (PNETs) in 2010 into three main group, which has not been widely and comprehensively evaluated. We aimed to validate the clinical valve of this system associated with the clinical outcome and long-term survival when applied to PNETs, which were rare and heterogeneous.

METHODS

We retrospectively collected and analyzed the data of 150 consecutive patients with PNETs who underwent a resection.

RESULTS

Sixty-four males and 86 females with PNETs were enrolled in our study. The clinical stage from I to IV by European Neuroendocrine Tumor Society were respectively defined in 53, 60, 19 and 18 patients. Seventy-two patients were pathologically diagnosed as neuroendocrine tumor G1 (NET G1), 48 as neuroendocrine tumor G2 (NET G2) and 30 as neuroendocrine carcinoma G3 (NEC G3). Patients with a radical resection obtained a notably higher overall survival (OS) than that of patients who underwent a palliative surgery (P=0.001). The 5-year OS of patients with NET G1 was significantly higher than that of patients with NET G2 (P=0.015) and NEC G3 (P<0.001); the comparison of OS for patients with NET G2 and NEC G3 was also statistically significant (P=0.005). In both univariate and multivariate analysis, clinical staging by ENETS (stage I and II vs. stage III and IV), resection (radical vs. palliative) and WHO 2010 grading classification (NET G1 and G2 vs. NEC G3) were validated to be independent predictors for the survivals of PNETs.

CONCLUSION

The newly-updated WHO 2010 grading classification was prognostic for the OS of PNETs and could be widely adopted in clinical practice.

Carbidopa-assisted 18F-fluorodihydroxyphenylalanine PET/CT for the localization and staging of non-functioning neuroendocrine pancreatic tumors

OBJECTIVE

CD premedication was found to increase the value of ¹⁸F-fluorodihydroxyphenylalanine (¹⁸F-FDOPA) PET/CT imaging in the detection of adult insulinoma. The aim of this study was to evaluate the performance of CD-assisted ¹⁸F-FDOPA PET/CT in the diagnosis and staging of non-functioning pNETs.

METHODS

Twenty consecutive patients with low-grade pNETs who underwent CD-assisted ¹⁸F-FDOPA PET/CT imaging and ¹¹¹In-somatostatin receptor scintigraphy (SRS) were evaluated. Histology was considered as the gold standard. In case where no surgical resection was performed, the diagnosis of pNET was made by the confrontation of the different available imaging modalities.

RESULTS

CD-assisted ¹⁸F-FDOPA PET/CT was positive in 18/20 cases (90 %), whereas SRS was positive in 13/19 cases (68 %). When considered the 19 patients underwent both nuclear medicine examinations, ¹⁸F-FDOPA PET/CT was significantly more sensitive then SRS for primary tumor detection (p = 0.049). False-negative results of both ¹⁸F-FDOPA PET/CT and SRS were observed in 2 cystic pNETs. SRS failed to detect one additional cystic tumor and 3 pNETs of 10, 12 and 17 mm, respectively. ¹⁸F-FDOPA PET/CT correctly identified all patients with lymphatic, visceral and bone metastases. SRS failed to detect lymphatic spread and was falsely negative in one patient with splenic metastasis.

CONCLUSIONS

Contrary to widely held assumptions, our study further expands the application of CD-assisted ¹⁸F-FDOPA PET/CT for non-functioning pNETs when ⁶⁸Ga-radiolabeled somatostatin analogs are not available.

Natural history and outcome in Chinese patients with gastroenteropancreatic neuroendocrine tumours: - a 17-year retrospective analysis

BACKGROUND

There is rising incidence of gastroenteropancreatic neuroendocrine tumours (GEP- NETs) in many parts of the world, but epidemiological data from Asian populations is rare.

METHODS

We conducted a retrospective study in a tertiary medical centre in Hong Kong, using updated diagnostic criteria. The presentation, clinical features, and disease outcome were reviewed for all patients with GEP-NETs confirmed histopathologically at the Prince of Wales Hospital, the Chinese University of Hong Kong, between 1996 and 2013, according to the latest 2010 World Health Organization Classification.

RESULTS

Among 126 patients, GEP- NETs were found in pancreas (34.9 %), rectum (33.3 %), and stomach (8.7 %), and most of them were non- functional GEP- NETs (91.3 %), mostly of grade 1 (G1) (87.3 %), and about 20 % had metastases on presentation. Age under 55 years, G1 tumours and absence of metastases were significant favourable predictors for survival in univariate analysis; whereas G2/3 tumours, size ≥2 cm, and metastases were significant predictors for disease progression (p < 0.05). In multivariate analysis, age and metastases on presentation were significant predictors of mortality (respective hazard ratios [HR] 1.05 [95 % confidence interval {CI} 1.02-1.08] and 6.52 [95 % CI 3.22-13.2]) and disease progression (respective HRs 1.05 [95 % CI 1.02-1.07] and 4.12 [95 % CI 1.96-8.68]), while higher tumour grade also independently predicted disease progression (HR 5.17 [95 % CI 2.05-13.05]) (all p < 0.05).

CONCLUSION

Non-functional tumours with non-specific symptoms account for the vast majority of GEP-NETs in this Chinese series. Multidisciplinary approach in the management of patients with GEP-NETs may help improve the treatment efficacy and outcome.

Animal models of spontaneous pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are usually low-grade neoplasms derived from the endocrine pancreas. PNETs can be functioning and cause well-described hormonal hypersecretion syndromes or non-functioning and cause only tumor mass effect. PNETs appear to be more common recently likely due to incidental detection by imaging. Although the diagnosis and management of PNETs have been evolving rapidly, much remains to be studied in the areas of molecular pathogenesis, molecular markers of tumor behavior, early detection, and targeted drug therapy. Unique challenges facing PNETs studies are long disease course, the deep location of pancreas and difficult access to pancreatic tissue, and the variety of tumors, which make animal models valuable tools for PNETs studies. Existing animal models of PNETs have provided insights into the pathogenesis and natural history of human PNETs. Future studies on animal models of PNETs should address early tumor detection, molecular markers of tumor behavior, and novel targeted therapies.

Pancreatic neuroendocrine tumor in a child of 3.5 years old

BACKGROUND

Pancreatic neuroendocrine tumor is rarely seen, particularly in children. One of the symptoms of this tumor is jaundice that may be misdiagnosed as the sign of hepatitis A, especially in countries with a high prevalence of this infectious disease.

METHODS

We present a 3.5-year-old girl with four weeks of icterus, who was misdiagnosed with hepatitis A.

RESULTS

The patient was finally diagnosed as having a low grade pancreatic neuroendocrine carcinoma.

CONCLUSION

Pediatricians should be aware of or consider a tumor in differential diagnosis of jaundice, especially prolonged one in children.

TNM staging of pancreatic neuroendocrine tumors: an observational analysis and comparison by both AJCC and ENETS systems from 1 single institution

We aimed to analyze the clinical characteristics and compare the surgical outcome of pancreatic neuroendocrine tumors (p-NETs) using the 2 tumor-node-metastasis (TNM) systems by both the American Joint Committee on Cancer (AJCC) Staging Manual (seventh edition) and the European Neuroendocrine Tumor Society (ENETS). Moreover, we sought to validate the prognostic value of the new AJCC criterion. Data of 145 consecutive patients who were all surgically treated and histologically diagnosed as p-NETs from January 2002 to June 2013 in our single institution were retrospectively collected and analyzed. The 5-year overall survival (OS) rates for AJCC classifications of stages I, II, III, and IV were 79.5%, 63.1%, 15.0%, and NA, respectively, (P < 0.005). As for the ENETS system, the OS rates at 5 years for stages I, II, III, and IV were 75.5%, 72.7%, 29.0%, and NA, respectively, (P < 0.005). Both criteria present no statistically notable difference between stage I and stage II (P > 0.05) but between stage I and stages III and IV (P < 0.05), as well as those between stage II and stages III and IV (P < 0.05). Difference between stage III and IV by ENETS was significant (P = 0.031), whereas that by the AJCC was not (P = 0.144). What's more, the AJCC Staging Manual (seventh edition) was statistically significant in both uni- and multivariate analyses by Cox regression (P < 0.005 and P = 0.025, respectively). Our study indicated that the ENETS TNM staging system might be superior to the AJCC Staging Manual (seventh edition) for the clinical practice of p-NETs. Together with tumor grade and radical resection, the new AJCC system was also validated to be an independent predictor for p-NETs.

Assessing the short- and long-term outcomes after resection of benign insulinoma

BACKGROUND

Insulinoma is a rare functional pancreatic neuroendocrine tumour (NET) believed to have an excellent long-term outcome, but few studies have solely focused on this issue after apparently curative resection. This study aimed to assess post-operative and long-term outcomes after resection of benign insulinomas.

METHODS

From 1998 to 2013, 36 consecutive patients with insulinomas underwent surgery. Three patients had multiple endocrine neoplasia type-1 (MEN-1). Demographics, operative findings, tumour grade (2010 World Health Organization (WHO) NET classification), post-operative pancreatic fistula (POPF) grade (International Study Group of Pancreatic Fistula (ISGPF)), complications and recurrence were analysed.

RESULTS

Eighteen (50%) had enucleation while the rest underwent pancreatic resection. The majority (86.1%) of insulinomas belonged to WHO NET grade G1. POPF occurred in 58.3% of patients while clinical fistula (ISGPF grades B and C) occurred in 19.4%. One (2.8%) patient required reoperation. The occurrence of POPF was not related to type of resection or surgical approach. There was no perioperative mortality. After a mean follow-up of 83.6 months, two patients (5.7%) developed disease recurrence at 34.4 and 131.9 months after initial surgery. No patients developed distant metastasis. The 10- and 15-year disease-free rates were 95.6 and 85.4%, respectively.

CONCLUSION

POPF occurred frequently and posed a significant morbidity after resection of insulinoma. However, it occurred independently of type of resection or surgical approach. Although the immediate cure rate after resection was high (100%), long-term disease recurrence in sporadic (non-MEN-1) cases was not insignificant. Regular long-term follow-up is recommended.

Quality of life, resource utilisation and health economics assessment in advanced neuroendocrine tumours: a systematic review

Neuroendocrine tumours (NET) are often diagnosed at an advanced stage when the prognosis is poor for patients, who often experience diminished quality of life (QoL). As new treatments for NET become available, it is important to characterise the associated outcomes, costs and QoL. A comprehensive search was performed to systematically review available data in advanced NET regarding cost of illness/resource utilisation, economic studies/health technology assessment and QoL. Four rounds of sequential review narrowed the search results to 22 relevant studies. Most focused on surgical procedures and diagnostic tools and contained limited information on the costs and consequences of medical therapies. Multiple tools are used to assess health-related QoL in NET, but few analyses have been conducted to assess the comparative impact of available treatment alternatives on QoL. Limitations include English language and the focus on advanced NET; ongoing terminology and classification changes prevented pooled statistical analyses. This systematic review suggests a lack of comparative economic and outcomes data associated with NET treatments. Further research on disease costs, resource utilisation and QoL for patients with advanced NET is warranted.

Mammalian target of rapamycin signaling activation patterns in pancreatic neuroendocrine tumors

BACKGROUND

Phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway dysregulation has been implicated in the development of various human cancers. However, expression of mTOR cascade components in pancreatic neuroendocrine tumors (PNETs) has not been fully explored. The aim of this study was to assess the expression of mTOR pathway in PNETs using immunohistochemistry.

METHODS

From December 1984 to April 2012, we surgically treated 42 patients with PNETs. We used immunohistochemistry to evaluate expression of mTOR, phosphorylated mTOR (p-mTOR), p70S6 kinase (S6K), phosphorylated S6 ribosomal protein (p-S6rp), eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), and phosphorylated 4E-BP1 (p-4E-BP1) in the resected specimens. The relation between the expression of these molecules and clinicopathological characteristics was investigated.

RESULTS

We identified the expression of mTOR (28.6%), p-mTOR (52.4%), S6K (52.4%), p-S6rp (40.5%), 4E-BP1 (81.0%), and p-4E-BP1 (26.2%) in PNETs. The expression of mTOR, p-mTOR, S6K, and p-S6rp was significantly associated with tumor invasion, proliferation, and an advanced-stage. Particularly, the expression of p-mTOR was related to clinically relevant factors such as tumor size, vascular invasion, extrapancreatic invasion, lymph node and/or distant metastasis, mitotic count, and European Neuroendocrine Tumor Society TNM staging as well as the 2004 and 2010 World Health Organization (WHO) classification. In addition, p-S6rp expression was related to vascular invasion, extrapancreatic invasion, lymph node and distant metastasis, mitotic count, and the 2010 WHO classification. In contrast, no significant relation between 4E-BP1 activation and clinicopathological factors was observed. The expression of p-mTOR was strongly correlated with that of p-S6rp (r = 0.474, P = 0.002).

CONCLUSIONS

Our results suggest that activation of the mTOR/S6K signaling pathway plays a significant role in tumorigenesis and progression of PNET.

Animal models and cell lines of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs), also known as islet cell tumors, are mostly indolent neoplasms that probably arise from a network of endocrine cells that includes islet cells and pluripotent precursors in the pancreatic ductal epithelium. The incidence and prevalence of PNETs continue to rise in recent years because of more sensitive detection. The molecular pathogenesis, early detection, molecular predictors of tumor behavior, and targeted drug therapy of PNETs are not well understood and require additional basic and translational research. The rarity and indolent nature of these tumors, difficulty of access to appropriate patient tissue samples, and varying histopathology and secreted hormones pose particular challenges to PNET researchers. Animal models and cell lines are indispensable tools for investigating the pathogenesis, pathophysiology, mechanisms for tumor invasion and metastasis, and therapeutics of PNETs. This review summarizes currently available animal models and cell lines of PNETs, which have provided valuable insights into the pathogenesis and natural history of human PNETs. In the future, animal models and cell lines of PNETs should also be used to study early tumor detection and molecular predictors of tumor behavior and to test the responses to, and mechanisms for, novel targeted drug therapies.

International practice patterns and resource utilization in the treatment of neuroendocrine tumors

OBJECTIVES

This study compared resource use and practice patterns in patients with advanced neuroendocrine tumors (NETs) on disease progression, across countries, and by tumor type.

METHODS

Physicians in the United States, United Kingdom, Germany, France, Brazil, and Italy completed data extraction forms to extract chart data of patients with NET relating to health care resource utilization and treatment practice. Data were assessed in a cross-sectional manner, by country, and by NET subtype. Univariate and multivariate analyses were performed to compare categories of resource use by disease progression status.

RESULTS

A total of 197 physicians provided data on 394 patients. Overall resource utilization was high across tumor types, countries, and progression. Nearly half of all patients received chemotherapy (49%); moreover, high rates of hospitalization (65%), surgery (47%), and use of somatostatin analog (77%) were observed, with lower rates of peptide receptor radionuclide therapy (10%) and targeted therapies (6%). These patterns were consistent across gastrointestinal tract/lung NET and pancreatic NET. However, a certain variation in resource utilization was observed across countries. Disease progression was associated with increasing utilization of chemotherapy, hospitalization, and targeted therapy.

CONCLUSIONS

Advanced NET is associated with significant resource use across subtypes and countries, and resource utilization is likely to increase on disease progression. There remains an unmet need for therapeutic options after disease progression.

Pancreatic neuroendocrine tumors: biology, diagnosis,and treatment

Pancreatic neuroendocrine tumors (PNETs), a group of endocrine tumors arising in the pancreas, are among the most common neuroendocrine tumors. The genetic causes of familial and sporadic PNETs are somewhat understood, but their molecular pathogenesis remains unknown. Most PNETs are indolent but have malignant potential. The biological behavior of an individual PNET is unpredictable; higher tumor grade, lymph node and liver metastasis, and larger tumor size generally indicate a less favorable prognosis. Endocrine testing, imaging, and histological evidence are necessary to accurately diagnose PNETs. A 4-pronged aggressive treatment approach consisting of surgery, locoregional therapy, systemic therapy, and complication control has become popular in academic centers around the world. The optimal application of the multiple systemic therapeutic modalities is under development; efficacy, safety, availability, and cost should be considered when treating a specific patient. The clinical presentation, diagnosis, and treatment of specific types of PNETs and familial PNET syndromes, including the novel Mahvash disease, are summarized.

Surgical treatment of sporadic pancreatic neuroendocrine tumors: a state of the art review

Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms. They are clinically diverse and divided into functioning and nonfunctioning disease, depending on their ability to produce symptoms due to hormone production. Surgical resection is the only curative treatment and remains the cornerstone therapy for this patient group, even in patients with advanced disease. Over the last decade there has been a noticeable trend towards more aggressive surgery as well as more minimally invasive surgery in patients with PNETs. This has resulted in improved long-term survival in patients with locally advanced and metastatic disease treated aggressively, as well as shorter hospital stays and comparable long-term outcomes in patients with limited disease treated minimally invasively. There are still controversies related to issues of surgical treatment of PNETs, such as to what extent enucleation, lymph node sampling, and vascular reconstruction are beneficial for the oncologic outcome. Histopathologic tumor classification is of high clinical importance for treatment planning and prognostic evaluation of patients with PNETs. A constant challenge, which relates to the treatment of PNETs, is the lack of an internationally accepted histopathological classification system. This paper reviews current issues on the surgical treatment of sporadic PNETs with specific focus on surgical approaches and tumor classification.

Gastric neuroendocrine tumours

BACKGROUND

Gastric neuroendocrine tumours (NETs) are increasingly recognised, and management decisions may be difficult due to an incomplete understanding of aetiology, natural history and optimum therapy. This article presents a current understanding based on recent advances in epidemiology, classification, molecular profiling, and treatment.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Gastric NETs may be divided into three clinical prognostic groups: type I is associated with autoimmune atrophic gastritis and hypergastrinaemia, type II is associated with Zollinger-Ellison syndrome, and type III lesions are gastrin-independent, have the greatest metastatic potential and poorest prognosis. There has been an increased frequency of gastric NETs reported. Management approaches have evolved in parallel with advances in endoscopic staging and surgery, as well as improved understanding of the biology and natural history of NETs.

CONCLUSIONS

Gastric NETs present a spectrum of activity from indolent tumours to metastatic malignancy. Treatment decisions for patients must be individualised and are best managed by a multidisciplinary team approach. The current evidence base is limited to small series and efforts to treat patients within clinical networks of expertise are warranted.

Incidental intraoperative discovery of a pancreatic neuroendocrine tumor associated with chronic pancreatitis

Pancreatic neuroendocrine tumors are a rare entity with an incidence between 2 per million to 5 per 100,000. Association with pancreatitis (acute or chronic) is rare and is considered to be determined by the tumoral obstruction of pancreatic ducts, but sometimes occurs without any apparent relationship between them. Non-functional neuroendocrine pancreatic tumors are usually diagnosed when either very large or metastatic. Small ones are occasionally diagnosed when imagery is performed for other diagnostic reasons. Intraoperative discovery is even rarer and poses problems of differential diagnosis with other pancreatic tumors. Association with chronic pancreatitis is rare and usually due to pancreatic duct obstruction by the tumor. We describe the case of a patient with a small non-functioning neuroendocrine tumor in the pancreatic tail accidentally discovered during surgery for delayed traumatic splenic rupture associated with chronic alcoholic pancreatitis. The tumor of 1.5 cm size was well differentiated and confined to the pancreas, and was resected by a distal splenopancreatectomy.

CONCLUSIONS

Surgeons should be well aware of the rare possibility of a non-functional neuroendocrine tumor in the pancreas, associated with chronic pancreatitis, surgical resection being the optimal treatment for cure. Histopathology is of utmost importance to establish the correct diagnosis, grade of differentiation, malignancy and prognosis.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2114470176676003.

Prognostic factors and characteristics of pancreatic neuroendocrine tumors: single center experience

PURPOSE

Pancreatic neuroendocrine tumors (PNET) are a rare subgroup of tumors. For PNETs, the predictive factors for survival and prognosis are not well known. The purpose of our study was to evaluate the predictive factors for survival and disease progression in PNETs.

MATERIALS AND METHODS

We retrospectively analyzed 37 patients who were diagnosed with PNET at Severance Hospital between November 2005 and March 2010. Prognostic factors for survival and disease progression were evaluated using the Kaplan-Meier method.

RESULTS

The mean age of the patients was 50.0±15.0 years. Eight cases (21.6%) were described as functioning tumors and 29 cases (78.4%) as non-functioning tumors. In univariate analysis of clinical factors, patients with liver metastasis (p=0.002), without resection of primary tumors (p=0.002), or American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) stage III/IV (p=0.002) were more likely to demonstrate shorter overall survival (OS). Patients with bile duct or pancreatic duct invasion (p=0.031), sized-lesions larger than 20 mm (p=0.036), liver metastasis (p=0.020), distant metastasis (p=0.005), lymph node metastasis (p=0.009) or without resection of primary tumors (p=0.020) were more likely to demonstrate shorter progression-free survival (PFS). In multivariate analysis of clinical factors, bile duct or pancreatic duct invasion [p=0.010, hazard ratio (HR)=95.046] and tumor location (non-head of pancreas) (p=0.036, HR=7.381) were confirmed as independent factors for predicting shorter PFS.

CONCLUSION

Patients with liver metastasis or without resection of primary tumors were more likely to demonstrate shorter OS. Patients with bile duct or pancreatic duct invasion or tumors located at body or tail of pancreas were more likely to demonstrate shorter PFS.

Radioguided surgery in neuroendocrine tumors using Ga-68-labeled somatostatin analogs: a pilot study

BACKGROUND

Previous studies of the intraoperative use of a hand-held gamma probe to localize metastases and primary tumors have shown improved assessment of tumor spread and changes in surgical management based on additional information gained by radioguided surgery (RGS).

PURPOSE

The aim was to test the feasibility and advantages of doing RGS using a gallium-68 labeled with somatostatin receptor analogs in the intraoperative detection of neuroendocrine tumors.

METHODS

Ga-68 somatostatin receptor PET/CT imaging was performed preoperatively in 9 patients with gastroenteropancreatic neuroendocrine tumors. Statistical analyses were performed to find out the correlation between the pathologic size of the tumor lesions and the maximum standardized uptake value on PET/CT as well as the target/nontarget ratio (T/NT) of gamma probe counts. Thereafter, the impact of the planned operation procedure and the lesion-based sensitivity of tumor detection (surgical palpation vs. PET/CT vs. gamma probe) had been observed.

RESULTS

Overall, 72 locations in 9 patients were examined intraoperatively using gamma probes. The gamma probe detected 94% of the whole histologically quantified lesions, whereas the PET/CT allocated 69% and surgical palpation, 50%. RGS resulted in change in the operative procedure in 56%. There was a significant correlation between the maximum standardized uptake value and tumor size (0.74; P < 0.005).

CONCLUSION

Hand-held gamma probe surgery using gallium-68-labeled somatostatin analogs is a feasible and an attractive option for real-time detection of small metastases and primaries of neuroendocrine tumors.

Pancreatic neuroendocrine tumors: a comprehensive review

Pancreatic neuroendocrine tumors (NETs) are a heterogeneous group of tumors. Despite being relatively rare, representing just 1-2% of all pancreatic neoplasms, the incidence of pancreatic NET has increased over the past two decades. Although the primary treatment for localized NET is surgical resection, there is still a lack of effective therapeutic options for patients with advanced unresectable pancreatic NET. Recently, the targeted agents sunitinib malate (SUTENT®, Pfizer Inc, NYC) and everolimus (AFINITOR®, Novartis, Basel, Switzerland)-both with different mechanisms of action-received United States Food and Drug Administration approval for the treatment of progressive, well-differentiated, pancreatic NET in patients with unresectable, locally advanced or metastatic disease. SUTENT® also received approval for this indication by the European Commission in 2010. Our article presents an overview of pancreatic NET, with a focus on their diagnostic work-up, clinical presentation and treatment options. Topics for further investigation of targeted therapy are also discussed.

Necrosis and angioinvasion predict adverse outcome in pancreatic neuroendocrine tumors after curative surgical resection: results of a single-center series

BACKGROUND

The prediction of outcome in pancreatic neuroendocrine tumors (P-NETs) still represents a challenge. Several clinicopathologic parameters have been proposed to predict adverse outcome. The aim of this study was to evaluate the impact of tumor necrosis and angioinvasion on the outcome after curative R0 resection of P-NETs.

METHODS

We reviewed our institutional experience over the last 30 years. A total of 82 patients with a mean age of 54 years (range 17-83 years) underwent surgical resection of P-NETs during the period from 1964 to 2006. There were 41 men and 41 women. The patients' outcomes after R0 surgical treatment were analyzed in relation to the presence or absence of tumor cell necrosis and angioinvasion as judged by histologic methods.

RESULTS

The overall (n = 82) 5-year survival was 52.4% (± 6.0%). Forty-eight of the patients underwent a R0 resection successfully. These patients showed a 5-year survival of 59.04% (± 7.8%); the median survival was 101 ± 36 months. Necrosis status was documented on 47 of the R0 resected patients (97.9%). The survival median of patients with tumor cell necrosis was significantly shorter than those without necrosis (41 ± 25 vs. 173 ± 69 months, respectively, P = 0.006). The patients' mean 5-year survival was also significantly decreased (28.9 ± 15.0% vs. 68.5.6 ± 8.9%). Angioinvasion status was documented on 43 of the R0 resected patients (90.0%). The median survival of these patients was decreased from 173 ± 51 to 54 ± 18 months when angioinvasion was observed in the histological sections (P = 0.104). The patients' mean 5-year survival was also decreased from 69.2 ± 9.3% to 35.9 ± 14.0%.

CONCLUSIONS

Long-term survival of patients with P-NETs is influenced by various pathologic factors. Among our patients, there was not a significant difference in overall survival based on the diameter of the primary tumor or the lymph node status after R0 surgical resection. The presence of necrosis in the TNM and World Health Organization classification for pancreatic endocrine tumor was associated with significant poor overall survival in each classification category. Hence, necrosis represents an independent variable for poor prognosis.

Non-functioning pancreatic neuroendocrine tumors--a case report and review of literature

PURPOSE

Neuroendocrine tumors of pancreas (PNET) are rare pancreatic neoplasms comprising 1-2% of all pancreatic tumors. The overall prognosis and long-term survival for PNET patients is far better than for patients with exocrine pancreatic cancer. PNETs are classified as functional or nonfunctional based on the presence or absence of a specific clinical syndrome associated with hormone oversecretion.

METHODS

We present the case of a 36-year-old female with epigastric and right upper quadrant abdominal pain for 3 months associated with decreased appetite, early satiety and a 20-lb weight loss. On examination, she was cachectic with hepatomegaly.

RESULTS

Laboratory assays showed elevated liver and pancreatic enzymes. On computed tomography (CT) scan of the abdomen and pelvis, there was a low-attenuation mass in the distal pancreatic tail measuring 4.7 × 2.4 cm with multiple liver masses, omental implants, left ovarian mass, and a small amount of ascites. CT-guided liver biopsy on pathology was consistent with a well-differentiated pancreatic neuroendocrine carcinoma with metastasis to the liver. Assays for biomarkers of pancreatic neuroendocrine tumors showed an elevated chromogranin A with normal to non-specific elevations of the rest.

CONCLUSIONS

The patient and her family declined palliative chemoembolization of the liver lesions or palliative chemotherapy and desired home hospice. We describe here the presentation and course of the case as well as a literature review of PNET with particular emphasis on nonfunctioning PNETs.

Cost-effectiveness of everolimus vs sunitinib in treating patients with advanced, progressive pancreatic neuroendocrine tumors in the United States

BACKGROUND

Everolimus (Afinitor) and sunitinib (Sutent) were recently approved to treat patients with advanced, progressive pancreatic neuroendocrine tumors (pNETs). (Afinitor is a registered trademark of Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA; Sutent is a registered trademark of Pfizer Inc., New York, NY, USA.) This analysis examined the projected cost-effectiveness of everolimus vs sunitinib in this setting from a US payer perspective.

METHODS

A semi-Markov model was developed to simulate a cohort of patients with advanced, progressive pNET and to estimate the cost per life-year gained (LYG) and per quality-adjusted life-year (QALY) gained when treating with everolimus vs sunitinib. Efficacy data were based on a weight-adjusted indirect comparison of the agents using phase 3 trial data. Model health states included: stable disease with no adverse events, stable disease with adverse events, disease progression, and death. Therapy costs were based on wholesale acquisition cost. Other costs such as physician visits, tests, hospitalizations, and adverse event costs were obtained from literature and/or primary research. Utility inputs were based on primary research. Sensitivity analyses were conducted to test the model's robustness.

RESULTS

In the base-case analysis, everolimus was associated with an incremental 0.448 LYG (0.304 QALYs) at an incremental cost of $12,673, resulting in an incremental cost-effectiveness ratio (ICER) of $28,281/LYG ($41,702/QALY gained). The ICER fell within the cost per QALY range for many widely used oncology drugs. Sensitivity analyses demonstrated that, overall, there is a trend that everolimus is cost-effective compared to sunitinib in this setting.

LIMITATIONS

Results of the indirect analysis were not statistically significant (p > 0.05). Assumptions that treatment patterns are the same across therapies may not represent real-world practice.

CONCLUSIONS

While the analysis is limited by its reliance on an indirect comparison of two phase 3 studies, everolimus is expected to be cost-effective relative to sunitinib in advanced, progressive pNET.

[Carcinoid tumors]

The authors review the most important clinical aspects of carcinoid tumors. Carcinoid tumors originating in neuroendocrine cells are rare, usually slowly-growing neoplasms, however, they may present as aggressive and rapidly progressing tumors. Epidemiologic data indicates that their prevalence is gradually increasing, which may be explained, at least in part, by the development and wider use of advanced diagnostic methods. A considerable proportion of patients with neuroendocrine tumors are symptom-free, whereas others may have carcinoid syndrome or symptoms of other endocrine syndromes. Early diagnosis may be established by the measurement of biochemical markers (serum chromogranin A, urinary 5-hydroxyindoleacetic acid) and advanced localization methods. A considerable number of patients are diagnosed at the late stages of the disease; in these cases surgical cure is not possible but surgical and/or interventional radiologic procedures which reduce tumoral mass should be still considered. The most effective drugs for symptomatic treatment of carcinoid tumors are somatostatin analogues; in addition to their beneficial effect on clinical symptoms they may stabilize tumor growth for many years and, less frequently, may produce tumor regression. The use of chemotherapeutic agents is considered in patients with aggressive, rapidly growing and advanced tumors; initial findings with temozolomide and thalidomide in clinical trials raise the possibility that these chemotherapeutic agents may prove to be new therapeutic options. Radioisotope-labeled peptide receptor therapy with 131 I-MIBG, 90 Y-DOTA-TOC or 177 Lu-DOTA-TOC may offer a highly effective option for patients with progressive and advanced stage of neuroendocrine tumors. Initial observations obtained in clinical trials with some tyrosine kinase inhibitors, antibodies against tyrosine kinases, and with inhibitors of mammalian target of rapamycin (mTOR) support the possibility that at least some of these new agents may have a role in future treatment options in patients with advanced neuroendocrine tumors.