Considerations concerning a tailored, individualized therapeutic management of patients with (neuro)endocrine tumours of the gastrointestinal tract and pancreas

Recent Advances in the Diagnosis and Management of Carcinoid Syndrome

Carcinoid syndrome, a paraneoplastic condition linked with the release of multiple humoral factors, affects around 30-40% of patients with well-differentiated neuroendocrine tumours. Carcinoid syndrome has a major and unfavourable impact on patients' quality of life; it raises costs when compared to non-functioning neuroendocrine tumours; and it causes patients' lifestyles to alter, such as food, job, physical activity, and social life. Somatostatin analogues have been the first-line therapy for individuals with neuroendocrine tumours and carcinoid disease for decades. While these drugs give considerable relief from carcinoid syndrome symptoms, clinical progression is unavoidable, necessitating further research into newer treatment measures. Carcinoid tumours are sometimes difficult to diagnose because of their vague or nonspecific symptoms. There have been several advancements in all aspects of carcinoid syndrome, as well as novel therapeutics, in the previous few years. New epidemiological studies show that it is becoming more common; increasing insights into the pathogenesis of its various clinical manifestations and its natural history: definition of prognostic factors; new methods to verify its presence; the development of new drugs to treat its various manifestations, both initially and in somatostatin-refractory cases; and an increased understanding of the pathogenesis, natural history, and management of the disease. An all language literature search was conducted on MEDLINE, COCHRANE, EMBASE, and Google Scholar till November 2021. The following search strings and Medical Subject Headings (MeSH) terms were used: "Recent advances", "Carcinoid syndrome", "Neuroendocrine Neoplasms" and "Carcinoid heart disease". We comprehensively reviewed the literature on the pathogenesis, clinical features, and newer treatment modalities for Carcinoid Syndrome. Recent advancements in research and management have resulted from advances in our understanding of the aetiology of carcinoid syndrome. The development of molecular indicators of aggressiveness improved serum tumour markers, and the molecular aetiology of carcinoid heart disease are all possible because of advances in molecular biology. We conducted a comprehensive review to update knowledge regarding the pathophysiology, diagnostic protocols, and current and newer treatments for carcinoid syndrome, which presently requires a multidisciplinary approach, due to the complexity of the illness's aetiology, diagnosis, and therapy.

When and How to Use Somatostatin Analogues

Long-acting depot formulations of the currently available somatostatin analogues are considered the first-line treatment for control of hormonal excess by hormone-producing neuroendocrine tumors of the gastrointestinal tract and pancreas. These drugs are currently also considered the first-line treatment for tumor control of both hormone-producing and non-hormone-producing neuroendocrine tumors of the gastrointestinal tract and pancreas. These drugs need coupling and interaction with specific somatostatin receptor subtypes, which are expressed on the cells of neuroendocrine tumors of the gastrointestinal tract and pancreas.

Carcinoid syndrome and perioperative anesthetic considerations

Carcinoid tumors are uncommon, slow-growing neoplasms. These tumors are capable of secreting numerous bioactive substances, which results in significant potential challenges in the management of patients afflicted with carcinoid syndrome. Over the past two decades, both surgical and medical therapeutic options have broadened, resulting in improved outcomes. The pathophysiology, clinical signs and symptoms, diagnosis, treatment options, and perioperative management, including anesthetic considerations, of carcinoid syndrome are presented.

New therapeutic options for metastatic malignant insulinomas

Insulinomas are the most common, functioning, pancreatic neuroendocrine tumours. The great majority (>90%) of insulinomas are nonmetastatic at presentation and can be surgically cured. The <10% patients with distant (liver-bone) metastases have a median survival of < 2 years. Everolimus and sunitinib have been recently introduced as targeted therapies for metastatic pancreatic neuroendocrine tumours. An additional advantage of everolimus in the treatment of patients with metastatic insulinomas is its capability to increase blood glucose levels. Peptide receptor radiotherapy using radiolabelled somatostatin analogues has also been shown to be successful in controlling tumour growth of metastatic pancreatic neuroendocrine tumours. In patients with metastatic insulinomas, this therapeutic modality was also effective in controlling hypoglycaemia, even in the presence of tumour regrowth. With the introduction of these new therapeutic modalities, the therapeutic arsenal for the 'tailor-made' approach of patients with metastatic insulinomas is further expanded.

Current surgical management of pancreatic endocrine tumor liver metastases

BACKGROUND

The management of metastatic disease in pancreatic endocrine tumors (PETs) demands a multidisciplinary approach and the cooperation of several medical specialties. The role of surgery is critical, even when a radical excision cannot always be achieved.

DATA SOURCES

A PubMed search of relevant articles published up to February 2011 was performed to identify current information about PET liver metastases regarding diagnosis and management, with an emphasis on surgery.

RESULTS

The early diagnosis of metastases and their accurate localization, most commonly in the liver, is very important. Surgical options include radical excision, and palliative excision to relieve symptoms in case of failure of medical treatment. The goal of the radical excision is to remove the primary tumor bulk and all liver metastases at the same time, but unfortunately it is not feasible in most cases. Palliative excisions include aggressive tumor debulking surgeries in well-differentiated carcinomas, trying to remove at least 90% of the tumor mass, combined with other additional destructive techniques such as hepatic artery embolization or chemoembolization to treat metastases or chemoembolization to relieve symptoms in cases of rapidly growing tumors. The combination of chemoembolization and systemic chemotherapy results in better response and survival rates. Other local destructive techniques include ethanol injection, cryotherapy and radiofrequency ablation.

CONCLUSION

It seems that the current management of PETs can achieve important improvements, even in advanced cases.

Presentation and outcome of pancreaticoduodenal endocrine tumors in multiple endocrine neoplasia type 1 syndrome

AIM

To assess presentation and outcome of pancreaticoduodenal endocrine tumors (PDETs) in a single center series of multiple endocrine neoplasia type 1 (MEN1) patients.

METHODS

Retrospective analysis of prospectively collected data of MEN1 patients observed at the University of Verona.

RESULTS

Thirty-one MEN1 patients had PDETs, including 16 nonfunctioning (NF), 6 insulinomas and 9 Zollinger-Ellison syndrome (ZES). In 16 of these patients (52%), PDET was the manifestation which led to the diagnosis of MEN1; among this group, 15 patients (94%) previously had unidentified primary hyperparathyroidism (PHPT), which was asymptomatic in 9 cases (60%). Of the 31 patients, 19 (61%) underwent curativesurgery and 13 (68%, 7 NF-PDETs, 4 insulinomas and 2 ZES) were disease-free after a median follow-up of 3 years (range: 0.5-15). One patient had debulking surgery with stable disease after 2 years of follow-up. Eight patients with NF-PDETs ≤20 mm and 2 with ZES, treated with a conservative approach, showed stable disease. One patient with insulinoma was lost to follow-up.

CONCLUSIONS

PDET may be the manifestation that leads to MEN1 diagnosis since the almost constant presence of PHPT is very often unrecognized or considered sporadic. Conversely, the presence of PDETs should be looked for in all patients presenting PHPT, even if asymptomatic, particularly before age 50. Surgery may be curative in the majority of insulinomas and can prolong disease-free survival in NF-PDET, but is not proven to be effective in ZES. A conservative approach can be safely reserved for patients with NF-PDETs ≤20 mm.

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

BACKGROUND

Neuroendocrine tumours of the pancreas (PNETs) represent 1-2% of all pancreatic tumours. The terms 'islet cell tumours' and 'carcinoids' of the pancreas should be avoided. The aim of this review is to offer an overview of the history and diagnosis of PNETs followed by a discussion of the available treatment options.

METHODS

A search on PubMed using the keywords 'neuroendocrine', 'pancreas' and 'carcinoid' was performed to identify relevant literature over the last 30 years.

RESULTS

The introduction of a revised classification of neuroendocrine tumours by the World Health Organisation (WHO) in 2000 significantly changed our understanding of and approach to the management of these tumours. Advances in laboratory and radiological techniques have also led to an increased detection of PNETs. Surgery remains the only treatment that offers a chance of cure with increasing number of non-surgical options serving as beneficial adjuncts. The better understanding of the behaviours of PNETs together with improvements in tumour localisation has resulted in a more aggressive management strategy with a concomitant improvement in symptom palliation and a prolongation of survival.

CONCLUSION

Due to their complex nature and the wide range of therapeutic options, the involvement of specialists from all necessary disciplines in a multidisciplinary team setting is vital to provide optimal treatment of this disease.

Pancreatic cytopathology: a practical approach and review

CONTEXT

Pancreatic cytopathology plays an important role in the diagnosis and management of patients with solid and cystic lesions of the pancreas.

OBJECTIVE

To serve as a practical guide to pancreatic cytopathology for the practicing pathologist. Data Sources.-A comprehensive assessment of the medical literature was performed.

CONCLUSIONS

We review pancreatic cytopathology, with specific discussions of its role in patient management, specimen types and specimen processing, specific diagnostic criteria, and the use of ancillary testing and advanced techniques.

Cytotoxic treatment including embolization/chemoembolization for neuroendocrine tumours

In patients with advanced neuroendocrine tumours, surgery is curative in only a minority of cases, whilst the anti-tumour effect of somatostatin analogues, despite efficient symptom control, is limited. Systemic chemotherapy has been proved to be effective only in certain tumour types. Although metastatic midgut carcinoids and well-differentiated gastrointestinal carcinoids are relatively insensitive to chemotherapy, pancreatic neuroendocrine tumours show a response rate of around 40% to streptozotocin-based combinations, particularly with fluorouracil and doxorubicin. Poorly differentiated tumours respond even better, especially to a combination of cisplatin and etoposide. In patients with predominant liver disease, ischaemia of tumour lesions induced by vascular occlusion by particle embolization or chemoembolization may be considered. This may have clinical and biochemical responses up to 80%, and objective responses up to 60%, in disease which is progressive despite previous treatments. Potential adverse effects and short duration of response should be taken into account.

Biochemistry of neuroendocrine tumours

Several circulating or urinary tumour markers can be used for the diagnosis and follow-up of functioning and clinically non-functioning neuroendocrine tumours of the pancreatic islet cells and intestinal tract. Among the specific tumour markers are serotonin and its metabolites--e.g. 5-hydroxyindoleacetic acid (5-HIAA)--in carcinoid tumours and the carcinoid syndrome, insulin and its precursors or breakdown products in insulinoma, and gastrin in gastrinoma. Plasma vasointestinal polypeptide (VIP) determinations have been used in the diagnosis of VIPoma, plasma glucagon for glucagonoma, and serum somatostatin for somatostatinoma. Among the tumour-non-specific markers are: chromogranins, neuron-specific enolase (NSE), alpha-subunits of the glycoprotein hormones, catecholamines, pancreatic polypeptide (PP), ghrelin and adrenomedullin.

Radioembolization with 90Yttrium Microspheres: A State-of-the-Art Brachytherapy Treatment for Primary and Secondary Liver Malignancies

Yttrium-90 microspheres are increasingly being used as a treatment modality for primary and secondary liver tumors. As these therapies continue to be accepted, it is natural that their application in more complex clinical scenarios will become more common. This article is meant to introduce these controversies and to generate interest and dialogue by the interventional oncology community. This discussion is based on more than 900 (90)Y radioembolization procedures performed over a 5-year period.

Regulation of Neuronal Nitric-oxide Synthase Activity by Somatostatin Analogs following SST5 Somatostatin Receptor Activation

Somatostatin receptor SST5 is an inhibitory G protein-coupled receptor that exerts a strong cytostatic effect on various cell types. We reported previously that the SST5 anti-proliferative effect results in the inhibition of mitogen-induced increases in intracellular cGMP levels and MAPK activity. This study was conducted to define the early molecular events accountable for the SST5-mediated anti-proliferative effect. Here, we demonstrate that, in Chinese hamster ovary cells expressing SST5 (CHO/SST5 cells), somatostatin inhibited cell proliferation induced by nitric oxide donors and overexpression of the neuronal nitric-oxide synthase (nNOS) protein isoform. Accordingly, nNOS activity and dimerization were strongly inhibited following SST5 activation by the somatostatin analog RC-160. In CHO/SST5 cells, nNOS was dynamically recruited by the SST5 receptor and phosphorylated at tyrosyl residues following RC-160 treatment. RC-160 induced SST5-p60(src) kinase complex formation and subsequent p60(src) kinase activation. Coexpression of an inactive p60(src) kinase mutant with SST5 blocked RC-160-induced nNOS phosphorylation and inactivation and prevented the SST5-mediated anti-proliferative effect. In CHO/SST5 cells, p60(src) kinase associated with nNOS to induce its inactivation by phosphorylation at tyrosyl residues following RC-160 treatment. Using recombinant proteins, we demonstrated that such phosphorylation prevented nNOS homodimerization. Next, surface plasmon resonance and mutation analysis revealed that p60(src) directly associated with nNOS phosphorylated Tyr604. SST5-mediated inhibition of nNOS activity was demonstrated to be essential to the RC-160 anti-proliferative effect on pancreatic endocrine tumor-derived cells. We therefore identified nNOS as a new p60(src) kinase substrate essential for SST5-mediated anti-proliferative action.

Malignant insulinoma in childhood

Pancreatic tumors constitute a rare surgical problem in infancy and childhood. Insulinomas are rare in all age groups with an estimated incidence of one per 250,000 person-years and even rarer in childhood. We report a 10 year-old girl with malignant insulinoma. The presenting symptom was hypoglycemic attacks. Laboratory investigation demonstrated that the hypoglycemia was due to hyperinsulinism. MRI of the abdomen revealed a mass at the tail of the pancreas. Distal pancreatectomy with splenectomy was performed. Histological examination showed malignant insulinoma with peripancreatic lymph node metastases. One month later abdominal MRI revealed the existence of multiple small metastatic foci in the liver, which were confirmed by In111 octreoscan. Treatment with octreotide was started and the disease is stable after 12 months of therapy.

IFN-beta is a highly potent inhibitor of gastroenteropancreatic neuroendocrine tumor cell growth in vitro

IFN-alpha controls hormone secretion and symptoms in human gastroenteropancreatic neuroendocrine tumors (GEP-NET) but it rarely induces a measurable tumor size reduction. The effect of other type I IFNs, e.g., IFN-beta, has not been evaluated. We compared the antitumor effects of IFN-alpha and IFN-beta in BON cells, a functioning human GEP-NET cell line. As determined by quantitative reverse transcription-PCR analysis and immunocytochemistry, BON cells expressed the active type I IFN receptor mRNA and protein (IFNAR-1 and IFNAR-2c subunits). After 3 and 6 days of treatment, IFN-beta significantly inhibited BON cell growth in a time- and dose-dependent manner. IC50 and maximal inhibitory effect on day 6 were 8 IU/mL and 98%, respectively. In contrast, the effect of IFN-alpha resulted significantly in a less potent effect (IC50: 44 IU/mL, maximal inhibition: 26%). IFN-alpha induced only cell cycle arrest, with an accumulation of the cells in S phase. IFN-beta, apart from a more potent delay in S-G2-M phase transit of the cell cycle, also induced a strong stimulation of apoptosis, evaluated by flow cytometry (Annexin V and 7-AAD) and measurement of the DNA fragmentation. Besides, only IFN-beta severely suppressed chromogranin A levels in the medium from BON cells after 6 days of treatment. In conclusion, IFN-beta is much more potent, compared with IFN-alpha, in its inhibitory effect on GEP-NET cell proliferation in vitro through the induction of apoptosis and cell cycle arrest. Further studies are required to establish whether IFN-beta has comparable potent tumor growth inhibitory effects in vivo.

Carcinoid syndrome: diagnosis and medical management

Gastro-intestinal carcinoids are slow growing tumors arising from enterochromaffin or Kulchitsky cells. Their clinical presentation depends on what combination of bioactive substances is secreted. Midgut carcinoid can present with the carcinoid syndrome in the presence of liver metastases. Its most typical clinical manifestations include cutaneous flushing and diarrhea. A nonspecific biochemical tumor marker for carcinoid tumors is serum chromogranin A and a specific marker for the carcinoid syndrome is the increased urinary excretion of 5-hydroxy indole acetic acid (5-HIAA). Localizing studies in carcinoid tumors/syndrome are: transabdominal ultrasonography (US), endoscopy, endoscopic US, videocapsule endoscopy, computerized tomography, magnetic resonance imaging, selective abdominal angiography, 111In-pentetreotide scintigraphy (and intraoperative radionuclide probe), 123I (131I)-metaiodobenzylguanidine (MIBG) scintigraphy, bone scintigraphy and 11C-5-HT positron emission tomography (PET). Therapies for carcinoid tumors/syndrome are: surgery, somatostatin analogs, interferon-alpha, radiotherapy, liver dearterialization, liver (chemo, or radio)-embolization, alcohol sclerotherapy of liver metastases, radiofrequency ablation of liver metastases, cryosurgery of liver metastases, occasionally liver transplantation, radiotherapy-coupled somatostatin analogs, 131I-MIBG and occasionally chemotherapy.

Endocrine pancreatic tumors: factors correlated with survival

BACKGROUND

The aim of this study was to evaluate the survival rate of patients with endocrine tumors of the pancreas, functioning or non-functioning, associated or not with MEN 1 syndrome.

PATIENTS AND METHODS

Eighty-three patients with pancreatic endocrine tumors diagnosed in our department from 1978 to 2003 were studied.

RESULTS

The study included 37 men (44.6%) and 46 women (55.4%). The median age of patients at diagnosis was 55 years (range 19-81 years). Fifty-two patients (62.7%) had non-functioning endocrine tumors, 16 (19.3%) had functioning endocrine tumors and 15 (18.1%) had MEN 1 disease with pancreatic involvement. Twenty-seven patients (32.5%) had liver metastases at the time of diagnosis, involvement of the lymph nodes was found in 47 out of 79 patients (59.5%). Forty patients (48.2%) had radical surgery, 20 (24.1%) had palliative surgery and 53 were treated medically. The survival rate was significantly related to the presence of metastases, lymph node involvement, and the type of tumor and treatment.

CONCLUSIONS

Tumor resection, the absence of liver and lymph node metastases, and the presence of MEN 1 syndrome are related to a better survival rate. Radical surgery continues to have a central role in the therapeutic approach to endocrine tumors of the pancreas.

Clinical endocrinology and metabolism. The somatostatin neuroendocrine system: physiology and clinical relevance in gastrointestinal and pancreatic disorders

Somatostatin is produced in enteroendocrine D cells and intrinsic neurons of the stomach, intestines and pancreas. Its physiologic actions are mediated primarily by somatostatin receptors type 2 and 5, and include the inhibition of secretion of most endocrine and exocrine factors. Diseases directly attributable to somatostatin excess or deficiency are rare, although there is a complex pathogenic relationship between persistent Helicobacter pylori infection and reduced somatostatin in chronic gastritis. Abundant somatostatin receptors on many neoplastic and inflammatory cells are the basis for sensitive in vivo imaging with radiolabeled somatostatin analogs and provide a therapeutic target. Current indications for somatostatin therapy include hormone-expressing neuroendocrine tumors, intractable diarrhea and variceal bleeding secondary to portal hypertension. Exciting advances are being made in the development of high-affinity nonpeptide analogs with receptor-subtype selectivity and increased bioavailability. Somatostatin analogs coupled to high-energy radionuclides show promise as novel cytotoxic agents for certain metastatic tumors.

Clinical endocrinology and metabolism. Gut endocrine tumours

Endocrine tumours of the gastrointestinal tract and pancreas may present at different disease stages with either hormonal or hormone-related symptoms/syndromes, or without hormonal symptoms. They may occur either sporadically or as part of hereditary syndromes. In the therapeutic approach to a patient with these tumours, excessive hormonal secretion and/or its effects should always be controlled first. A team approach is needed to achieve a balanced opinion on the use of the different therapeutic options in patients with these tumours.