Treatment of malignant endocrine pancreatic tumours with human leucocyte interferon

Neuroendocrine tumors with syndromic vasoactive intestinal polypeptide hypersecretion: a retrospective study

Aim: Vasoactive intestinal polypeptide producing neuroendocrine tumors are rare and cause severe hormonal symptoms. Patients/methods: Eighteen patients with vasoactive intestinal polypeptide producing neuroendocrine tumors were analyzed with reviews of medical records, radiology and tumor tissue specimens. Results: Twelve patients (67%) had liver metastases at diagnosis. Chemotherapy, somatostatin analogs and interferon were given as medical therapies. Streptozocin/5-fluorouracil produced an objective response in 40% of the evaluable patients. Somatostatin analogs gave a clinical/biochemical response in eight out of nine patients. Transarterial embolization of the liver and peptide receptor radionuclide therapy was given to refractory cases. Sixteen patients died during the observation period. The median overall survival from diagnosis was 102 months. Conclusion: Systemic chemotherapy and somatostatin analogs should be given in cases of advanced disease or for hormonal symptoms.

Systemic Therapies for Advanced Gastrointestinal Carcinoid Tumors

Well-differentiated gastrointestinal neuroendocrine tumors (GINETs) tend to be slow growing, but treatment of advanced disease remains a challenge. Somatostatin analogues (SSAs) are considered standard therapy for carcinoid syndrome. SSAs delay tumor progression in advanced well-differentiated gastroenteropancreatic NETs. Cytotoxic chemotherapy and interferon play a limited role in the treatment of nonpancreatic GINETs. There is no standard approach to treatment of patients with disease progression. Identification of systemic agents with antitumor activity in advanced disease remains an unmet medical need. Enrollment to clinical trials is encouraged; potential therapeutic targets include the vascular endothelial growth factor and mammalian target of rapamycin signaling pathways.

Therapeutic strategies for neuroendocrine liver metastases

Patients who have neuroendocrine tumors frequently present with liver metastases. A wide panel of treatment options exists for these patients. Liver resection with curative intent achieves the best long-term results. Highly selected patients may be considered for liver transplantation. Substantial recurrence rates reported after surgical approaches call for neoadjuvant and adjuvant concepts. Liver-directed, locally ablative procedures are recommended for patients with limited, nonresectable tumor burden. Angiographic liver-directed techniques, such as transarterial embolization, transarterial chemoembolization, and selective internal radiotherapy, offer excellent palliation for patients with liver-predominant disease. Peptide receptor radionuclide therapy is a promising palliative procedure for patients with hepatic and/or extrahepatic metastases. The efficacy of these treatment options needs to be evaluated in randomized trials. Somatostatin analogues have demonstrated effectiveness not only for symptomatic relief in patients with secreting tumors but also for the control of proliferation in small intestinal neuroendocrine tumors and most recently also in those originating from the pancreas. Chemotherapy is an option mainly for those with pancreatic neuroendocrine tumors and high-grade tumors irrespective of the origin. Novel drugs targeting specific pathways within the tumor cell have produced improved progression-free survival compared with placebo in patients with pancreatic neuroendocrine tumors. Despite such a diverse armamentarium, there is uncertainty with regard to the optimal treatment regimens. Newly introduced molecular-based markers, along with the conduction of clinical trials comparing the efficacy of treatment modalities, offer a chance to move the treatment of neuroendocrine tumor disease toward personalized patient care. In this report, the authors review the approaches for treatment of neuroendocrine liver metastases, identify shortcomings, and anticipate future perspectives. Furthermore, clinical practice recommendations are provided for currently available treatment options. Although multiple modalities are available for the treatment of neuroendocrine liver metastases, optimal management is unclear. The current knowledge pertaining to these treatment options is analyzed.

Management of patients with hepatic metastases from neuroendocrine tumors

Neuroendocrine tumors have a disposition toward metastasis to the liver. A range of treatment modalities for neuroendocrine liver metastases is available in the clinical arena, the indications for which depend on tumor characteristics such as patterns of metastasis, tumor grade, and anatomical origin. The complete surgical resection of liver deposits represents the only option with the intent to cure and is the gold standard approach, whereas cytoreductive resection (debulking) presents another surgical option aiming to ameliorate the symptoms and prolong survival. Liver transplantation is generally an accepted option for highly selected patients. For patients ineligible for radical surgery, liver-directed therapies-transarterial embolization/chemoembolization, selective internal radiotherapy, and local tumor ablation-present alternative strategies. Systemic therapies include peptide receptor radiotherapy, somatostatin analogues, cytotoxic chemotherapeutics, and novel molecularly targeted drugs. However, despite the variety of treatments available, there exists little evidence to guide optimal clinical practice with currently available data predominantly retrospective in nature. In this review, we discuss the diagnostic procedures that influence the trajectory of treatment of patients with neuroendocrine liver metastases before critically appraising the evidence pertaining to these therapeutic strategies.

Systemic treatment in unresectable metastatic well-differentiated carcinoid tumors: consensus results from a modified delphi process

OBJECTIVES

This study aimed to develop expert consensus for the use of systemic treatments for unresectable metastatic well-differentiated (grade 1-2) carcinoid tumors using the RAND/UCLA modified Delphi process.

METHODS

After a comprehensive literature review, 404 patient scenarios addressing the use of systemic treatments for carcinoid tumors were constructed. A multidisciplinary panel of 10 physicians assessed the scenarios as appropriate, inappropriate, or uncertain (on a 1-9 scale) or as an area of disagreement before and after an extended discussion of the evidence.

RESULTS

Experts were medical and surgical oncologists, interventional radiologists, and gastroenterologists. Among rated scenarios, disagreement decreased from 14% before the meeting to 4% after. Consensus statements about midgut carcinoids included the following: (1) Somatostatin analogs are appropriate as first-line therapy for all patients; (2) In patients with uncontrolled secretory symptoms, it is appropriate to increase the dose/frequency of octreotide long-acting repeatable up to 60 mg every 4 weeks or up to 40 mg every 3 weeks as second-line therapy for refractory carcinoid syndrome. Other options may also be appropriate. Consensus was similar for non-midgut carcinoids.

CONCLUSIONS

The Delphi process provided a structured methodological approach to assist clinician experts in reaching consensus on the appropriateness of specific medical therapies for the treatment of advanced carcinoid tumors.

Biotherapies for GEP-NETs

Biological treatment for GI neuroendocrine tumours (NETs) includes treatment with somatostatin analogues and alpha interferons. Both of these therapies were developed in the early 1980's and initially for treatment of a carcinoid syndrome in patients with small intestinal NETs. Later on tumour biology studies indicated that well differentiated NETs (G1-tumours) benefit from treatment with somatostatin analogues and alpha interferons. Both agents give symptomatic improvement in patients with functioning tumours in 40-60% of the patients, biochemical responses in 50-70% of the patients and significant tumour shrinkage in 5-10% of the patients. Combination therapy with somatostatin analogues and alpha interferon has demonstrated some clinical benefit.

IN CONCLUSION

Somatostatin analogues and alpha interferons are still playing an important role and considered to be first-line treatment in functioning and in non-functioning well-differentiated NETs, (G1-tumours) and somatostatin analogues might also be applied to control clinical symptoms in G2-tumours with higher proliferation.

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.

Pancreatic islet cell carcinoma presenting with concurrent Cushing's and Zollinger-Ellison syndromes: case series and literature review

Cushing's syndrome and Zollinger-Ellison syndrome occur occasionally as a result of neuroendocrine cancers. The concurrence of the two syndromes has been considered to confer a poor clinical and therapeutic outcome. In this study, we are reviewing two patients with pancreatic islet cell carcinomas and with both Zollinger-Ellison and Cushing's syndromes, one followed up for more than 5 years, and the other still receiving therapy, 5 years since diagnosis. A literature review showed that surgery has limited utility as the majority of these patients had metastases at the time of diagnosis. Proton-pump inhibitors, ketoconazole, and somatostatin antagonists have a major role in controlling symptoms. Interferon and systemic chemotherapeutic agents play a role in the management of metastatic and fast-growing cases. Chemoembolization and bland embolization show encouraging results in controlling liver metastases. The latter was used effectively and more than once in the two patients presented herein. On the basis of recent molecular genetics studies, target therapy may be helpful, however, ongoing trials will define it's utility. As the data confers a worse prognosis versus other pancreatic neuroendocrine tumors, the relatively favorable outcome of the two patients reported herein may reflect the impact of multiple therapeutic modalities.

Treatment of endocrine pancreatic tumors

Endocrine pancreatic tumors are rare with an incidence of 4 per million inhabitants. Most tumors are malignant except for insulinomas that usually are benign. They are slowly growing in the majority of cases but there are exceptions with rapidly progressing malignant carcinomas. Because of the rarity of these tumors large randomized trials are difficult to accomplish. However, most physicians treating these patients agree that surgery should be considered in all cases and that medical treatment with chemotherapy and biotherapy is well established for this group of patients.

Medical treatment of gastrinomas

Gastrinomas are functional neuroendocrine tumors of the gastroenteropancreatic system. Surgery is first line treatment in gastrinomas, however often fails to be curative. This manuscript reviews current strategies of medical treatment of surgically non-curable gastrinoma. Symptomatic treatment with H(+)-K(+)-ATPase proton-pump inhibitors suppresses hypersecretion of gastric acid and substantially improves quality of life in patients with Zollinger-Ellison syndrome. Further medical therapy is only recommended in cases of progressive metastatic gastrinoma. In well differentiated neuroendocrine carcinoma (G1 and G2) a so-called biotherapy with somatostatin analogues exists as first-line and chemotherapy with streptocotozin plus doxorubicine/5-FU as second-line medical treatment option. In poorly differentiated neuroendocrine carcinoma (G3) chemotherapy with etoposide plus cisplatin is possible. Prospective future therapeutic strategies may include treatment with novel somatostatin analogues as well as angiogenesis inhibitors and kinase inhibitors targeting tumor-specific signaling cascades.

Endocrine pancreatic tumors: diagnosis and treatment

Endocrine pancreatic tumors (EPTs) are uncommon, having an incidence of one per 100,000 people. They may appear as sporadic tumors or be associated with hereditary syndromes. EPTs are categorized as functioning or nonfunctioning tumors, based on the presence or absence of clinical syndromes. Among the former, insulinomas and gastrinomas are the most common. For the histopathological investigation of EPTs, chromogranin A and synaptophysin immunostainings are recommended. Measurement of circulating chromogranin A is also the cornerstone for the biochemical diagnosis of these tumors. Furthermore, specific hormones produced and released by the neoplastic cells can be identified by immunostaining and used for biochemical evaluation. To locate EPTs, both noninvasive (ultrasonography, computerized tomography, MRI and radionuclear imaging) and invasive techniques (arterial stimulation with venous sampling) can be used. Debulking procedures (surgery, radiofrequency ablation, embolization/chemoembolization and liver transplantation) and/or medical treatment (chemotherapy, biotherapy and peptide receptor radionuclide therapy) are the options available for the treatment of EPTs. Understanding the molecular events underlying the pathobiology of EPTs will aid the development of more accurate diagnostic/prognostic markers and give guidance for improved therapeutic modalities.

Endocrine pancreatic tumors with glucagon hypersecretion: a retrospective study of 23 cases during 20 years

BACKGROUND

Glucagon-secreting endocrine pancreatic tumor is a rare disease, hence controlled studies on clinical management are lacking. In an attempt to assess the efficacy of diagnostic and therapeutic measures in patients with glucagonoma, a retrospective study was performed using the archives of a tertiary care center.

PATIENTS AND METHODS

Records from 340 patients with endocrine pancreatic tumors were reassessed and 23 patients with malignant endocrine pancreatic tumor and elevated plasma glucagon levels were identified.

RESULTS

About 7% of patients with histologically verified tumors fullfilled our criteria for glucagonoma. Only 22% of these patients had developed diabetes prior to the diagnosis of glucagonoma. Seventy eight percent had metastatic disease to the liver at diagnosis. Necrolytic migratory erythema was diagnosed or clinically suspected in 52%. Somatostatin receptor scintigraphy was positive in 95%. Nineteen patients received chemotherapy at some point, in 18 cases streptozotocin and 5 FU. With this treatment, objective radiological responses were seen in 50% of evaluable patients. Other treatment modalities used were interferon, somatostatin analogs, hepatic artery embolization, radio-frequency ablation of liver metastases, and radiolabeled somatostatin analogs. During the study period, 11 patients died at a median of 80 months from diagnosis whereas 11 patients are still alive after a median follow up of 52 months. One patient was lost to follow-up.

CONCLUSIONS

Glucagonomas represent 7% of our comprehensive referral material of endocrine pancreatic tumors. Necrolytic migratory erythema was a common finding (52%) and diabetes less frequent at presentation than previously reported. Tumors were positive on somatostatin receptor scintigraphy and objective responses were seen to chemotherapy.

Neuroendocrine tumors. Biotherapy

This review gives an introduction to the classification and staging of neuroendocrine tumors, as the prognostic implications of these classifications influence therapeutic decisions. The indications for biotherapy are given, together with a short update on the mechanism of somatostatin analogs and interferon-alpha therapy. This is followed by an in-depth description of the use of biotherapy, its results with respect to symptomatic and antiproliferative treatment, as well as its side-effects.

Treatment of malignant endocrine pancreatic tumors with a combination of alpha-interferon and somatostatin analogs

Somatostatin analogs and alpha-interferon induce good responses as single drugs in the treatment of endocrine pancreatic tumors. We examined the efficacy and tolerability of the combination of alpha-interferon and somatostatin analogs in 16 patients with metastatic endocrine pancreatic tumors. All patients except one had received prior treatment and were in a progressive state. Doses of alpha-interferon and somatostatin analogs were individually titrated. The alpha-interferon doses varied between 9 and 25 million units per week and were combined with 100-1500 microg of octreotide or 6000 microg of lanreotide daily. Radiological response was seen in 3 of 16 (19%) patients (median duration 23 mo). Biochemical response was seen in 10 of 16 (62.5%) patients (median duration 22 mo). All three patients previously progressing on both alpha-interferon and somatostatin analog as single drugs achieved a stabilization of the disease when treated with the combination (median duration 10 mo). Seven of eight (88%) patients previously progressing on alpha-interferon treatment benefited from the combination with biochemical partial response or stabilization. All six patients previously progressing during somatostatin analog treatment achieved biochemical partial response or stabilization. More than 80% of patients who progressed during previous treatment with either drug benefited from the combined treatment, which also was well tolerated. Thus, a combination of alpha-interferon and somatostatin analogs may be considered for patients previously progressing on treatment with alpha-interferon or somatostatin analogs. However, in this study, the value of sequential treatment has not been evaluated.

Hepatic cytoreduction followed by a novel long-acting somatostatin analog: a paradigm for intractable neuroendocrine tumors metastatic to the liver

BACKGROUND

Optimal management of symptomatic neuroendocrine tumors that metastasize to the liver is controversial. We investigated aggressive hepatic cytoreduction and postoperative administration of octreotide long-acting release (LAR), a long-acting somatostatin analog.

METHODS

Between December 1992 and August 2000, 31 patients underwent hepatic surgical cytoreduction (20 carcinoid, 10 islet cell, and 1 medullary). All patients had progressive symptoms refractory to conventional therapy.

RESULTS

Hepatic cytoreduction (resection, cryosurgery, and/or radiofrequency ablation) eliminated symptoms in 27 patients (87%) and decreased secretion of hormones by an overall mean of 59%. When minor symptoms returned and/or hormonal levels increased during follow-up, adjuvant therapy was started. Ten patients received adjuvant octreotide LAR once a month, and 21 received other adjuvants. At a median postoperative follow-up of 26 months, 16 patients had progressive/recurrent disease, 13 had died of their disease, and 2 remained free of disease. Median symptom-free interval was 60 months (95% confidence interval, 48-72) with octreotide LAR and 16 months (95% confidence interval, 10-29) with other adjuvants (P = .0007). Two-year symptom-free survival rate was 100% with octreotide LAR and 33% with other adjuvants.

CONCLUSIONS

Hepatic surgical cytoreduction can palliate progressive symptoms associated with liver metastases from intractable neuroendocrine tumors. Postoperative adjuvant therapy with octreotide LAR can prolong symptom-free survival.

Endocrine tumours of the pancreas: review and recent advances

Pancreatic endocrine tumours (PET) are rare but nonetheless important to recognize and treat in a timely fashion. Significant morbidity occurs due to excess secretion of hormones, with all of the PET having some degree of malignant potential. Surgeons must plan directed operative strategies to deal with these tumours and be prepared to undertake aggressive palliative debulking resections if indicated. Somatostatin receptor scintigraphy and endoscopic ultrasound have been particularly helpful in both localizing and staging patients with PET. Other important advances in management include the use of long-acting somatostatin analogues to inhibit hormonal secretion and tumour growth. The possibility of multiple endocrine neoplasia type 1 (MEN-1) should be considered in any patient with a PET. The present article will review the various classes of PET, describe MEN-1 in relation to PET and examine advances in imaging and localization. The role of surgery for PET is also discussed in the present review.

Islet cell tumors of the pancreas: the medical oncologist's perspective

Islet cell tumors of the pancreas are rare, indolent, neuroendocrine tumors. Approximately 50% of the patients diagnosed with these tumors present with symptoms related to various biologically active hormones that are secreted by these neoplasms. Currently, the only curative treatment for islet cell tumors is complete surgical resection. Management of metastatic disease is conservative. Initial treatment of these tumors includes expectant observation and medical management of symptoms with clinical monitoring and serial CT scans to assess tumor growth. Patients with rapidly progressive disease, with local symptoms caused by tumor bulk, or with uncontrolled symptoms related to hormone secretion require more aggressive medical or surgical intervention. The somatostatin analogue octreotide may help control hormone secretion and stabilize tumor growth. Patients refractory to octreotide with tumor predominantly in the liver are potential candidates for mechanical ablative techniques, such as hepatic arterial embolization. Radiofrequency ablation and cryosurgical techniques may also be useful, although specific data are limited. Surgical resection of metastatic disease may offer palliative relief of symptoms related to hormone secretion in carefully selected patients. Chemotherapy may be used for palliation when ablative techniques have failed or when significant extrahepatic disease is present. Streptozicin-based combinations remain the first line standard, but major objective responses are less common than had been previously thought. Because of the overall modest success of current chemotherapeutic regimens, patients with advanced disease in need of treatment should be encouraged to enroll in clinical trials testing newer antineoplastic agents or newer treatment strategies.

Surgical Experience with Nonfunctioning Neuroendocrine Tumors of the Pancreas

Nonfunctioning neuroendocrine tumors of the pancreas are rare slow-growing tumors with a more indolent natural history compared with pancreatic adenocarcinoma. This retrospective report reviews the surgical experience with nonfunctioning neuroendocrine tumors in an academic referral center. Statistical analysis was performed using Student's t test and Kaplan-Meier method compared with log-rank tests. Thirty-eight patients (24 males and 14 females) underwent surgery for a neuroendocrine tumor of the pancreas from 1984 through 1999. Twenty-eight patients with a mean age of 59.9 years had nonfunctioning islet cell tumors and 10 patients with a mean age of 59.1 years had functioning islet cell tumors (four gastrinomas, three glucagonomas, two insulinomas, and one vipoma). The nonfunctioning islet cell tumors were located in the head, neck, or uncinate process in 14 patients (50%), the body in seven (25%), and the tail in seven (25%). Operative procedures for the nonfunctioning islet cell tumors included nine pancreaticoduodenectomies, 12 distal pancreatectomies, three palliative bypasses, and four exploratory laparotomies without a resection or bypass. Mean survival for the four patients explored and not resected or bypassed was 7 months. Median survival for node-negative patients was 124 months, for node-positive patients 75 months, and for patients with metastasis to the liver 9 months. Estimated 2-year actuarial survival for the node-negative patients was 77.8 per cent, for node-positive patients 71.4 per cent, and for patients with metastasis to the liver 36.4 per cent. Six patients (60%) with node-negative disease, three (43%) with node-positive disease, and one (9%) with metastasis to the liver are alive at a mean follow-up of 41.8 months (range 1–167). Significant differences in median survival and 2-year survival were demonstrated between the node-positive/node-negative patients and those with metastasis to the liver ( P = 0.003). Patients with localized nonmetastatic disease should be considered for pancreatic resection as estimated median survival is 75 months or greater. Hepatic metastasis is a major predictor of survival.

[Drug therapy of endocrine neoplasms. Part II: Malignant gastrinomas, insulinomas, glucagonomas, carcinoids and other tumors]

BACKGROUND

The thyroid gland and the adrenal glands are the most common sites of endocrine carcinomas (see Part I of this review, Med Klin 2000;95: 20-5, Nr. 1). Less frequent are endocrine malignancies of the gastrointestinal tract (gastrinomas, insulinomas, glucagonomas, carcinoids and others).

TREATMENT

Because of the rarity and missing prospective studies as well as radiotherapy and chemotherapy resistance of these tumors, generally accepted conventional therapy guidelines for these endocrine carcinomas do not exist. Surgery and radionucleotide treatment should be considered as first line therapy. Somatostatin analogs (octreotide) are frequently used as well. Chemotherapy is usually not effective. Common substances are streptozotocin, 5-fluorouracil, doxorubicin, dacarbazine and cyclophosphamide.

Metastatic jejunal VIPoma: beneficial effect of combination therapy with interferon-alpha and 5-fluorouracil

The VIPoma syndrome is rare. It is usually caused by a neuroendocrine tumor located in the pancreas. Somatostatin analogs and interferon-a can be helpful in the symptomatic control of the disease, but the efficacy of chemotherapy in metastatic disease is limited. We report the case of a 32-yr-old patient who had a primary intestinal VIPoma with peritoneal carcinomatosis and hepatic metastases. Somatostatin analogs and conventional chemotherapy regimens were not effective on VIPoma syndrome and tumor progression. The combination of 5- fluorouracil and interferon-alpha was associated with a major clinical improvement and tumor regression. Further investigations should evaluate the place of such a combination as a first line treatment for patients with metastatic neuroendocrine tumors.

The effect of Zollinger-Ellison syndrome and neuropeptide-secreting tumors on the stomach

Zollinger-Ellison syndrome (ZES) is caused by a tumor that secretes gastrin and is the most common of the malignant islet cell tumors. ZES leads to hypergastrinemia, which, in turn, causes an overproduction of gastric acid and results in complications of peptic ulcer disease. Of all the islet cell tumors, gastrinoma tumors have undergone the most extensive study, providing a model of tumor management. Increased awareness and improved biochemical and radiologic techniques mean that these disorders are being recognized in more patients. Advances in the management of gastric acid secretion and new localization methods have significantly reduced the morbidity and mortality associated with ZES. The use of intravenous proton pump inhibitors such as pantoprazole will make surgical and perioperative management more favorable for patients. Radiologic and nuclear medicine studies permit the detection of the majority of islet cell tumors and improve the ability for surgical resection. With the recent cloning of the gene for multiple endocrine neoplasia type I (MEN-I) and the recognition of tumor markers associated with the development of islet cell tumors, early detection of these tumors may someday be possible.

Vasoactive intestinal polypeptide-secreting tumours: biology and therapy

VIP-secreting tumours are rare, but they produce a dramatic clinical picture, the most prominent feature being profuse, watery diarrhoea and hypokalaemia. VIPomas are malignant and require sophisticated diagnostic and localization techniques in order to identify their presence. Delays in diagnosis are the rule rather than the exception. Improvements in the diagnosis of VIPomas appear to result in an increase in resectability rates. A definitive diagnosis is aided by the determination of plasma VIP concentrations through the use of sensitive radioimmunoassays. With heightened awareness of this syndrome, increasing numbers of patients can be identified and more effective treatments developed for the refractory and recurrent tumours.

Gastrointestinal endocrine tumours. Gastrinoma

Since the description of the Zollinger-Ellison syndrome in two patients in 1955, there have been significant advances in the understanding of its pathogenesis, natural history, relationship to multiple endocrine neoplasia type 1, diagnosis, methods of tumour localization and management. The main focus in treatment is now shifting from management of the gastric acid hypersecretory state which can now be controlled medically in almost every patient, to the management of the gastrinoma. Recent studies are beginning to provide insights into the natural history of gastrinomas, factors that are associated with invasiveness in some gastrinomas, defining the role of surgery in managing patients with different disease extents, or with MEN 1 and being able to provide insights into molecular abnormalities that may be important in their pathogenesis. In this article each of these advances is briefly reviewed with emphasis primarily on recent advances.

Islet cell tumors of the pancreas

Pancreatic endocrine neoplasms are a heterogeneous group of tumors that produce active hormones and result in distinct clinical syndromes. For the most part, they are malignant and require sophisticated diagnostic and localization techniques in order to identify their presence. Delays in diagnosis are the rule rather than the exception. Improvements in the diagnosis of gastrinomas and insulinomas appear to result in an increase in resectability rates. The widespread availability of intraoperative ultrasonography, as well as improved knowledge of the location of these tumors, has also had an impact on improved cure rates. With heightened awareness of these syndromes, increasing numbers of patients can be identified and more effective treatments developed for the refractory and recurrent tumors.

Management of patients with Zollinger-Ellison syndrome

Zollinger-Ellison syndrome (ZES) is caused by gastrin-secreting tumors called gastrinomas. Patients commonly present with peptic ulcer disease and may have recurrent, multiple, and atypically located ulcers, e.g. in the jejunum. Alternatively, severe diarrhea may be the only presenting symptom. Patients with multiple endocrine neoplasia Type I (MEN-I) and ZES become symptomatic at an earlier age than patients with sporadic ZES. Patients with ZES have elevated fasting serum gastrin concentrations (> 100 pg/ml) and basal gastric acid hypersecretion (> 15 mEq/h). The secretin stimulation test is the best test to distinguish ZES from other conditions resulting in elevated gastrin levels. Gastric acid hypersecretion can be controlled in virtually all patients with H2-receptor antagonists or omeprazole, thus rendering total gastrectomy unnecessary. Computed tomography (CT), magnetic resonance imaging (MRI), radionuclide octreotide scanning, endoscopic ultrasound, and the selective arterial secretin injection test are the recommended imaging studies for localization of gastrinoma; nevertheless, 50% of gastrinomas are not evident on preoperative imaging studies. All patients with sporadic gastrinoma who do not have unresectable metastatic disease should undergo exploratory laparotomy for potential curative resection. With increased awareness of duodenal tumors, gastrinoma can be found in 80-90% of patients. Surgery may be the most effective treatment for metastatic gastrinoma if most or all of the tumor can be resected. The management of patients with MEN-I and ZES remains controversial. Some clinicians advocate an aggressive surgical approach, whereas others have had little success in rendering patients eugastrinemic.

Neuroendocrine metastases of the liver

Neuroendocrine liver metastases are rare, yet they represent an entity that has attracted much attention lately. The protracted course of neuroendocrine tumors and the hormone origin of their typical incapacitating symptoms constitute a logical basis for well founded and bespoke treatment. Demonstration of the liver secondaries is best done by ultrasonography (US) and contrast-enhanced computed tomography (CT), which on the whole have replaced the invasive angiography techniques. By use of histochemical and molecular biologic methods the exact nature of the tumor can be typified in tissue samples obtained percutaneously, laparoscopically, or surgically. Localization of nonpalpable metastases of the liver is best done by intraoperative US. Surgical removal of liver metastases is curative in some cases and is usually effective in relieving the symptoms. Also, palliative debulking or cytoreductive surgery is often worthwhile as it offers a chance of prolonged survival and symptom relief. Similar benefits are achieved by ischemic therapy preferably by temporary dearterialization, which in our department is done on an outpatient basis using a specially designed (externally controlled) occluder applied during a single laparotomy that includes debulking when appropriate as well as cholecystectomy. Hormonal therapy with somatostatin analogs may be used as a single treatment or in combination with ischemic therapy. It has an ensured symptom-reducing effect, whereas its influence on tumor growth is unsettled. Lately similar effects have been ascribed to human leukocyte interferon. In conclusion the specific characteristics of neuroendocrine tumors and the available treatment arsenal favor an active treatment approach in patients who have developed liver metastases.

Pancreatic vipomas: spectrum of presentation and evolution of diagnostic and therapeutic modalities

Two patients are reported who presented with symptoms characteristic of a pancreatic vipoma. The necessity to measure more than one plasma VIP level for diagnosis, and the delay between the onset of illness and diagnosis is illustrated by both cases. Evidence suggests that vipomas are still under reported. The evolution of sophisticated diagnostic and therapeutic modalities over the twenty-five years separating both presentations is discussed.

Clinical and biochemical effects in vivo of monoclonal antitumor antibody in Verner-Morrison's syndrome

BACKGROUND

Monoclonal antibodies have not been evaluated in metastasizing endocrine tumors, even though these lesions may induce severe morbidity of hormone excess in absence of considerable tumor burden.

METHODS

A murine monoclonal antibody of the IgG2a subtype was generated by immunization with dispersed tumor cells from an endocrine pancreatic carcinoma associated with liver and peritoneal metastases as well as a therapy-resistant Verner-Morrison's syndrome.

RESULTS

Immunohistochemical staining disclosed selective tissue reactivity of the antibody and conspicuous immunostaining on the surface of the tumor cells. Infusion of 100 mg antibody over 2 days into the common hepatic artery of the patient was accompanied by reduced diarrhea volume until death 6 weeks later and transient elevation of total plasma immunoreactivity for vasoactive intestinal peptide due to large molecular forms of the peptide. Postmortem examination demonstrated disappearance of peritoneal metastases as well as absence of immunostaining for the injected antibody and the transferrin receptor within residual hepatic tumors.

CONCLUSION

The results substantiate that symptomatic alleviation and perhaps interference with tumor cell mass may be obtained with monoclonal antibodies in patients with endocrine tumors and that the antiidiotypic immunoglobulin response may play a role herein.

An evaluation of human recombinant alpha interferon in patients with metastatic gastrinoma

BACKGROUND

Metastatic gastrinoma is becoming increasingly recognized in patients with Zollinger-Ellison Syndrome. The mean 5-year survival of these patients is < 20%. Chemotherapeutic regimens are of limited benefit. The aim of this study was to evaluate the use of interferon in these patients because a preliminary report suggested it might be effective.

METHODS

The efficacy and toxicity of interferon was assessed in 13 consecutive Zollinger-Ellison syndrome patients with liver metastases. Patients were treated with human recombinant alpha interferon (5 million IU, subcutaneously [SC]) daily and followed up at 3-month intervals with multiple imaging studies. At each follow-up, toxicity of therapy was assessed and fasting serum gastrin concentrations were obtained.

RESULTS

No patient showed a reduction in tumor size at any follow-up. One patient died after 2 months. At 6 months, six patients (46%) had stable tumor size in the liver, although new bone metastases developed in one patient. Three patients showed stable disease for up to 21 months. Changes in serum gastrin correlated with tumor response at 6 months. All patients developed some side effects of therapy. Thirty-one percent required dose reduction, and one patient (8%) had to have interferon therapy interrupted briefly.

CONCLUSIONS

These results fail to define a therapeutic role for interferon in the treatment of metastatic gastrinoma.

Review article: the management of Zollinger-Ellison syndrome

Awareness of the sometimes subtle features of Zollinger-Ellison syndrome is important in order not to miss the diagnosis. Immediately after initial diagnostic tests, the patient should be given antisecretory medication, while tests for the type of Zollinger-Ellison syndrome and tumour extent can be delayed. Acid output should be decreased to < 10 mmol/h to control symptoms and prevent complications. Histamine H2-antagonists remain the best available intravenous therapy but omeprazole is the most effective long-term oral therapy and has proved to be safe in nearly 10 years of continuous use. The management of the gastrinoma has changed in recent years since the discovery that the majority of gastrinomas arise outside the pancreas. Exploratory surgery with tumour resection is the treatment of choice in sporadic Zollinger-Ellison syndrome but there are few indications for surgery in patients with Zollinger-Ellison syndrome and multiple endocrine neoplasia type-1. None of the available therapies for metastatic gastrinoma is very effective.

Palliative treatment of neuroendocrine tumors

Effective palliation of patients with incurable neuroendocrine tumors requires both control of hormonal overproduction symptoms as well as control of tumor growth. Several important advances have been made in recent years toward these two goals. Octreotide and omeprazole have both been extremely effective in ameliorating hormonal symptoms of carcinoids, islet cell tumors and medullary thyroid carcinoma. Newer cytotoxic chemotherapy regimens and interferon have increased response rates over traditional therapy. More aggressive surgical extirpation of metastatic disease has also been beneficial.

Prospective comparative study of ability of MR imaging and other imaging modalities to localize tumors in patients with Zollinger-Ellison syndrome

The role of magnetic resonance (MR) imaging in patients with pancreatic endocrine tumors such as Zollinger-Ellison syndrome (ZES) is controversial. In the present study we have examined the ability of current MR imaging compared with other imaging modalities, to localize gastrinomas in 43 patients with ZES. All results were subsequently assessed at exploratory laparotomy (N = 34) or by liver biopsy (N = 9). For the 18 patients with metastatic gastrinoma in the liver, MR imaging had a sensitivity of 83%, ultrasound 50%, CT 56%, and angiography 61%. The combination of MR imaging, ultrasound, and CT were the same as MR imaging alone. For MR imaging, both T1 and STIR sequences had equal sensitivity, although tumors were more easily seen with STIR sequences. Specificity of MR imaging was slightly lower (88%) than the other modalities (96-100%) because MR imaging incorrectly identified small hemangiomas as possible tumors in four patients. MR imaging was better than CT in identifying metastatic lesions in the liver. For the localization of primary gastrinoma, assessed in 32 patients, MR imaging had a sensitivity of 25%, ultrasound 19%, CT 28%, all three together 38%, and angiography 59%. Localization of metastatic gastrinoma in the liver or primary gastrinomas in 16 patients was assessed before and after gadolinium-DTPA (0.1 mmol/kg). The sensitivity and specificity of MR imaging was unchanged but bolus injection and rapid MR acquisition techniques were not used. These results indicate that recent advances in MR imaging have greatly improved its sensitivity for the detection and assessment of the extent of metastatic gastrinoma. MR imaging is now the imaging study of choice to assess metastatic pancreatic endocrine tumors in the liver. In contrast, the detection of primary tumors by MR imaging has not improved; therefore, angiography remains the study of choice.

Hepatic arterial chemoembolization in patients with liver metastases of endocrine tumors. A prospective phase II study in 24 patients

BACKGROUND

Liver metastases of endocrine tumors are of major prognostic significance. The various therapeutic approaches have given disappointing results; however, locoregional treatment has allowed transient control of hepatic tumor growth.

METHODS

Twenty-four patients with liver metastases of endocrine tumors (mainly carcinoid tumors [n = 18] and gastrinomas [n = 5]) were included in a Phase II study of hepatic arterial chemoembolization (CE). Metastases were bilateral in all patients and invaded more than 50% of the liver in 12. They were synchronous of the primary tumor in 62.5% of the patients. Seventeen patients had not responded to previous intravenous chemotherapy. CE courses were performed every 3 months using an emulsion of 10 ml of iodized oil and doxorubicin 50 mg/m2 injected into tumor vessels, followed by CE arterial occlusion with gelatin sponge particles. Seventy-one CE courses were performed in 23 patients; there was one technical failure.

RESULTS

Among patients with carcinoid tumors, disappearance of diarrhea and/or flushing was observed in 8 of 11. Serotonin and/or its metabolite 5-hydroxyindoleacetic acid levels decreased by more than 50% in 57% of the patients. The size of liver metastases decreased by at least 50% in 6 of 18 patients, i.e., in 33% (range, 12-54%). Two had complete responses. The median duration of the responses was 14 months (range, 6-40). Among patients with noncarcinoid tumors, minor response or stabilization occurred in three of five patients. Major side effects were bleeding peptic ulcer (one patient) and oligoanuric renal failure (one patient). Abdominal pain, fever, and increases in hepatic enzyme levels were common and transient.

CONCLUSIONS

These results suggest that CE is effective in patients with liver metastases of endocrine tumors, mainly in carcinoids. In the latter, CE allows control of the carcinoid syndrome and regression or stabilization of the liver tumors in 80% of patients.

An update of the medical treatment of malignant endocrine pancreatic tumors

In the present study, we have updated our results with chemotherapy, alpha-interferon, octreotide and combinations of treatment modalities in patients with malignant endocrine pancreatic tumor (EPT). In our patient material of 134 EPT, 92 subjects had malignant tumors as evidenced by the presence of metastases or growth into adjacent organs. Seventy-eight patients had liver metastases. Streptozotocin plus 5-fluorouracil produced objective responses in 17/31 (54%) patients with a median duration of response of 23 months. The use of 5-HT3-antagonists as antiemetics has dramatically improved the quality of life during treatment by reducing the frequency of nausea to only 12.5%. The objective response rate to alpha-interferon (alpha-IFN) treatment, given as first-line treatment in 29 patients and after chemotherapy in 28 patients, was 51% (29/57) with a median duration of response of 20 months. Octreotide, which is still used as third-line treatment in most patients, produced significant biochemical responses in 6/19 (31%) patients with a median duration of 16 months. Combinations of alpha-IFN plus chemotherapy and a alpha-IFN plus octreotide in a small number of patients might indicate additive or synergistic effects. The median survival from start of treatment in the 92 malignant cases was 56.5 months, and for those with liver metastases (n = 78) at start of treatment 50 months. In conclusion, there are at least three effective therapies for malignant EPT and by combining them simultaneously or consecutively, a median survival of more than four years can be obtained.

Recombinant interferon alpha-2b in patients with metastatic apudomas: effect on tumours and tumour markers

Malignant carcinoid tumours, islet cell tumours and medullary carcinomas of the thyroid are tumours with similar clinical features. In patients with unresectable or metastatic tumours leukocyte interferon (IFN) and recombinant human (rh) IFN have demonstrated efficacy. Twenty-four evaluable patients with progressive tumours were treated with 2.5 megaunits rh IFN alpha-2b, administered once daily subcutaneously, for a median duration of 7 months (range 0.5-37+). Two carcinoid patients demonstrated a response in tumour size, 80% showed stable disease (SD). Sixty percent of the carcinoid patients with elevated urinary 5-hydroxyindoleacetic (5-HIAA) levels reached a biochemical partial response of the urinary 5-HIAA levels (median duration 13.5 months). In the patients with an islet cell or medullary tumour and an elevated tumour marker, the marker did not further increase. Of the 12 carcinoid patients evaluable for a symptomatic response, ten (83%) experienced a relieve of symptoms. IFN alpha-2b dose reduction or discontinuation due to toxicity was necessary in three and ten patients, respectively. No neutralising IFN alpha-2b antibodies developed despite prolonged treatment. In conclusion, IFN alpha-2b had a beneficial effect in patients with progressive tumours, while long-term IFN alpha-2b treatment did not augment neutralising antibodies. In view of the IFN alpha-2b-related toxicity, administration of IFN alpha-2b on alternating days may be preferable.

Gastroenteropancreatic endocrine tumors: effect of Sandostatin on tumor growth. The German Sandostatin Study Group

One hundred fifteen gastroenteropancreatic (GEP) patients with malignant endocrine tumors entered a prospective multicenter trial (12 patients with gastrinoma, 53 with carcinoid syndrome, 45 with nonfunctioning tumors, and five with other endocrine GEP tumors) to determine the efficacy of 200 micrograms Sandostatin three times a day in the control of tumor growth. This interim report describes the results in 85 patients. Thirty-four patients died, 14 before and 20 after the first follow-up investigation, indicating a "negative" selection of patients included in the trial and suggesting that Sandostatin cannot prevent disease progress when it is far advanced. In the evaluation of 68 patients monitored for at least 3 months, partial regression was observed in 4.4%, stable disease in 50%, and tumor progression in 45%. However, an initially favorable response frequently occurred with a decrease in response later: 54.4% at 3 months to 38% at 12 months for the whole group of patients. Proven inhibition of tumor growth was mirrored by suppression of serum and urine hormone parameters. It is concluded that Sandostatin exerts a beneficial effect on tumor growth in patients with metastatic endocrine GEP tumors. This beneficial effect decreases with time and is as yet unpredictable in the individual patient.

Streptozocin-doxorubicin, streptozocin-fluorouracil or chlorozotocin in the treatment of advanced islet-cell carcinoma

BACKGROUND

The combination of streptozocin and fluorouracil has become the standard therapy for advanced islet-cell carcinoma. However, doxorubicin has also been shown to be active against this type of tumor, as has chlorozotocin, a drug that is structurally similar to streptozocin but less frequently causes vomiting.

METHODS

In this multicenter trial, we randomly assigned 105 patients with advanced islet-cell carcinoma to receive one of three treatment regimens: streptozocin plus fluorouracil, streptozocin plus doxorubicin, or chlorozotocin alone. The 31 patients in whom the disease did not respond to treatment were crossed over to chlorozotocin alone or to one of the combination regimens.

RESULTS

Streptozocin plus doxorubicin was superior to streptozocin plus fluorouracil in terms of the rate of tumor regression, measured objectively (69 percent vs. 45 percent, P = 0.05), and the length of time to tumor progression (median, 20 vs. 6.9 months; P = 0.001). Streptozocin plus doxorubicin also had a significant advantage in terms of survival (median, 2.2 vs. 1.4 years; P = 0.004) that was accentuated when we considered long-term survival (greater than 2 years). Chlorozotocin alone produced a 30 percent regression rate, with the length of time to tumor progression and the survival time equivalent to those observed with streptozocin plus fluorouracil. Crossover therapy after the failure of either chlorozotocin alone or one of the combination regimens produced an overall response rate of only 17 percent, and the responses were transient. Toxic reactions to all regimens included vomiting, which was least severe with chlorozotocin; hematologic depression; and, with long-term therapy, renal insufficiency.

CONCLUSIONS

The combination of streptozocin and doxorubicin is superior to the current standard regimen of streptozocin plus fluorouracil in the treatment of advanced islet-cell carcinoma. Chlorozotocin alone is similar in efficacy to streptozocin plus fluorouracil, but it produces fewer gastrointestinal side effects than the regimens containing streptozocin. It therefore merits study as a constituent of combination drug regimens.

Zollinger-Ellison syndrome

As clinical experience with patients with ZES has grown, increasing recognition has been made of the broad spectrum of symptoms associated with gastrinomas. Diarrhea and acid-induced esophageal injury have taken their place alongside chronic peptic ulcer disease as indications for screening for gastrinoma. Diagnostic testing should begin with fasting serum gastrin levels and should include intravenous secretin infusion if fasting serum levels of gastrin are nondiagnostic and the patient is not found to be hypochlorhydric. Tumor localization is critical to aid in the identification of patients with potentially curable localized disease. Preoperative evaluation utilizing CT scanning with intravenous contrast should be done early and should be supplemented by other imaging modalities as necessary. Exploratory laparotomy, including a thorough examination of the duodenum and perhaps intraoperative ultrasound, should be performed in all patients with sporadic gastrinoma who lack evidence of extensive metastatic disease on preoperative evaluation. By utilizing this approach, it is likely that at least 20% of patients with ZES can be cured. With the availability of the highly effective H(+)-K(+)-ATPase inhibitor omeprazole, excellent control of symptoms related to gastric acid hypersecretion can be expected. Patients with unresectable gastrinoma may thus avoid potentially morbid antisecretory surgery and be managed with a fairly simple medical regimen. Further developments in the chemotherapeutic management of these patients with unresectable disease should be forthcoming in the future.

Therapeutic strategies in the management of endocrine GEP tumours

The therapeutic principles in the management of endocrine gastroenteropancreatic (GEP) tumours include surgical extirpation of the primary tumour in the absence of metastases and medical control of symptoms in the preoperative phase. In the presence of metastases only palliative procedures are available. Tumour growth might be controlled by surgical procedures as debulking of tumour masses, medically by chemotherapy and more recently by new developments as a long-acting somatostatin analogue (SMS 201-995) and alpha-interferon. Their efficacy is currently evaluated in prospective studies. In contrast to inhibition of growth symptoms derived from excessive hormone production by GEP tumours can be well controlled. SMS 201-995 effectively prevents or at least improves flush and diarrhoea in the carcinoid syndrome, disabling diarrhoea in the Verner-Morrison syndrome and migratory erythema in the glucagonoma syndrome. SMS acts by inhibition of hormone release from the tumour and by a direct mechanism at the site of the target cell via SMS receptors present on tumour and target cells. For control of acid hypersecretion in gastrinoma patients omeprazole is superior to all former and present alternatives and replaced total gastrectomy completely. A similarly effective drug to prevent hypoglycaemia due to uncontrolled insulin release from insulinomas is not available since neither SMS nor diazoxide are effective in every insulinoma patient.