Clinical efficacy of octreotide in the treatment of metastatic neuroendocrine tumors. A study by the Italian Trials in Medical Oncology Group

Hepatic artery embolization for control of symptoms, octreotide requirements, and tumor progression in metastatic carcinoid tumors

Hepatic artery embolization (HAE) has been utilized for treatment of advanced hepatic carcinoid metastases, with promising symptom palliation and tumor control. Our institution employs transcatheter HAE using Lipiodol/Gelfoam for treatment of carcinoid hepatic metastases, and this report presents our experience with twenty-four patients, examining symptom control, quality-of-life, octreotide dependence, and tumor progression. Twenty-four (11 male, 13 female, mean age = 59.4 +/- 2.5 yr) patients with carcinoid and unresectable hepatic metastases, confirmed by urinary 5-hydroxyindole acetic acid (5-HIAA) measurement and biopsy, were treated with Lipiodol/Gelfoam HAE from 1993-2001. Median follow-up was 35.0 months. Before HAE, 14 patients (58.3%) had malignant carcinoid syndrome, with symptoms quantified using our previously reported Carcinoid Symptom Severity Score, and 13 patients (54.2%) required octreotide for symptom palliation. Following treatment, symptom severity, octreotide dose, and tumor response were measured. Asymptomatic patients did not develop symptoms or require following treatment. Hepatic metastases remained stable (n = 4) or decreased (n = 19) in 23 patients (95.8%). Mean pretreatment Symptom Severity Scores (3.8 +/- 0.2), decreased to 1.4 +/- 0.1 post-treatment (P < 0.00001), with 64.3% of patients becoming asymptomatic. Mean pretreatment octreotide dosages (679.6 +/- 73.0 microg/d), decreased to 262.9 +/- 92.7 microg/d (P = 0.0024) post-treatment, with 46.2% of patients discontinuing octreotide. There were no treatment-related serious complications or deaths. This study demonstrates that Lipiodol/Gelfoam HAE produces excellent control of malignant carcinoid syndrome, allowing patients to decrease or eliminate use of octreotide, while controlling hepatic tumor burden.

Evaluation of (111)In-pentetreotide, (131)I-MIBG and bone scintigraphy in the detection and clinical management of bone metastases in carcinoid disease

Bone metastases are assumed to be rare in carcinoid disease and to be associated mainly with bronchial primaries. The aim of the present study was to evaluate the occurrence of bone metastases in patients with metastatic carcinoid tumours, and the role of various nuclear medicine modalities (bone scintigraphy, (111)In-pentetreotide and (131)I-MIBG) in its detection and clinical management. Nine (2 women, 7 men, median age 65 years) out of 86 consecutive carcinoid patients treated between 1987 and 1998 developed bone metastases (10%) with a median interval of 37 months between the diagnosis of metastatic carcinoid and bone metastases. Seven of them had non-bronchial primaries. (111)In-pentetreotide scintigraphy failed to detect the bone lesions in 50% of the cases, and (131)I-meta-iodobenzylguanidine(MIBG) scintigraphy in almost 80% of cases. Standard bone scintigraphy, however, was positive in all. Pain relief of bone metastases by means of radiation therapy was obtained in 5 of 6 patients. In another patient palliation of pain symptoms was obtained with Rhenium-186-hydroxyethylidene diphosphonate. Octreotide, Interferon of MIBG were ineffective for this purpose. It is concluded that bone metastases in carcinoid patients may be missed on (131)I-MIBG and (111)In-pentetreotide scintigraphy. Bone scintigraphy is a sensitive imaging technique. Diagnostic nuclear medicine modalities may be helpful in the clinical management of carcinoid disease.

Somatostatin analogues in the treatment of endocrine tumors of the gastrointestinal tract

Somatostatin and its long-acting analogues have been introduced for the treatment of endocrine tumours of the gastrointestinal tract as they have been shown to effectively control symptoms resulting from excessive hormone release in patients with carcinoid, Verner-Morrison and glucagonoma syndromes. This beneficial effect is due to the presence of somatostatin receptors in high densities on the majority of endocrine tumours. The symptomatic effect is less pronounced in insulinomas, since 30 - 50% of these tumours lack or express only a few somatostatin receptors. With respect to symptomatic control, somatostatin receptor subtypes 2 and 5 are the most important and the currently available long-acting analogues octreotide and lanreotide bind preferentially to these receptor subtypes. Long-term studies have shown that somatostatin analogues are safe and that the most important adverse advent is the development of gallstones. The antiproliferative potency of somatostatin and its analogues in vitro and in experimental tumour models prompted a number of studies in patients with metastatic endocrine tumours that are generally unresponsive to conventional chemotherapeutic protocols. Stabilisation of tumour growth lasting for months to a few years was the most favourable result, occurring in 30 - 70% of patients. However, definite proof of antiproliferative potency in man is still pending since placebo-controlled studies are not available. Radioligand therapy based on 111Indium, 90Yttrium and 177Lutetium coupled to somatostatin analogues via bifunctional chelators is currently under investigation with promising data concerning long-lasting control of symptoms and tumour growth from Phase I trials.

The clinical role of somatostatin analogues as antineoplastic agents: much ado about nothing?

BACKGROUND

Somatostatin (SST) analogues represent a novel approach for the treatment of certain cancers. The objective of this article is to summarise the current knowledge on SST analogues in the treatment of cancer patients.

METHODS

Computerised (Medline) and manual searches were performed to identify publications on clinical trials published in the English-speaking literature between 1966 and 2000. Information abstracted included patients' pre-treatment status, histology, SST receptor (SSTR) evaluation, type of SST analogue, application schedule and dose, duration of treatment, side-effects, response criteria applied (i.e. WHO response criteria, biochemical criteria or symptomatic investigations) and survival.

RESULTS

Our search disclosed 22 case reports, five phase 1 and 47 phase II trials, and eight randomised clinical trials using SST analogues (octreotide, lanreotide and vapreotide) as antineoplastic agents. With regard to the phase II trials, conflicting results have been demonstrated in almost all tumour entities investigated. The few randomised studies published so far have shown an impact on survival in patients with hepatocellular cancer, while the effect attributed to treatment in patients with gastrointestinal adenocarcinomas might well have been due to an exceptionally short survival in the control group. There appears to be evidence that SST analogues are able to enhance the therapeutic effects of hormonal intervention in patients with breast cancer, prostate cancer and probably pancreatic cancer. Interpretation of the findings, however, is complicated by the fact that patients were heavily pre-treated in some studies and response criteria have not been uniformly applied. In addition, most studies have not been designed to distinguish between receptor-mediated (direct) and indirect effects of SST analogues in tumour patients.

CONCLUSIONS

According to the results obtained so far, there can be no doubt about the wide therapeutic index and the high efficacy of SST analogues in the symptomatic management of neuroendocrine tumours. Apart from these indications, the data do not justify recommendation of SST analogues as antineoplastic agents outside of clinical trials, as the optimal dose and schedule of application for antineoplastic activity has not been defined for currently used agents. Carefully designed clinical trials including investigation of SSTR status before treatment, evaluation of an indirect mechanism of SST analogues, and assessment of optimal combination of hormone therapy and chemotherapy with SST analogues are clearly needed in the near future.

Efficacy of a chemotherapy combination for the treatment of metastatic neuroendocrine tumours

OBJECTIVES

Neuroendocrine tumours (NETs) are heterogeneous neoplasms for which there is no standard treatment. We have previously proposed an effective polychemotherapy (5-fluorouracil, dacarbazine and epirubicin), which only produced objective responses of brief duration. The present study aimed to assess in a multidisciplinary manner the efficacy of the same regimen at intensified doses in patients with advanced NETs.

PATIENTS AND METHODS

Eighty-two consecutive patients entered the study, of whom 21 had inoperable, locally advanced disease and 61 had metastatic disease. Seventy-two patients were evaluated for objective, biochemical and subjective responses. Response rate, time to progression (TTP) and overall survival (OS) were evaluated based on histotype.

RESULTS

An objective response was observed in 20 patients (intention-to-treat and standard analysis 24.4% and 27.8%, respectively). Complete biochemical and subjective responses were obtained in 25.1% and 38.9% of the cases. The median duration of treatment was 4 months and the objective responses had a median duration of 38 months. After a 60-month follow-up the median TTP and OS were 21 and 38 months, respectively.

CONCLUSIONS

Our polychemotherapy regimen is effective, with long duration, and is well tolerated both for gastroenteropancreatic and lung NETs, as well as for tumours with a more aggressive clinical behaviour. The new WHO endocrine tumour histotyping, examining also the tumour biology, may give additional information for selecting patients to chemotherapy.

The clinical management of neuroendocrine tumors with long-acting repeatable (LAR) octreotide: comparison with standard subcutaneous octreotide therapy

Neuroendocrine tumors are rare, occurring in less than 1% of the population. They are divided clinically into functionally active or non-active tumors. Functionally active tumors produce a variety of substances (mainly peptides or serotonin) that are responsible for symptoms and sometimes can lead to the death of the patient independently from tumor proliferation. The most important compounds that can control symptoms in these patients are somatostatin analogs. Native somatostatin is not suitable for long-term clinical application due to its short half-life. Therefore, synthetic drugs were developed with improved pharmacokinetic characteristics. The best-characterized analog, octreotide, has been successfully applied to patients with functioning tumors. Octreotide can ameliorate symptoms in 30%-70% of the patients, mainly through a direct inhibitory effect on hormone production from the tumors. There is little or no effect on tumor growth during octreotide therapy; clinical responses were recorded in only 10%-30% of the patients. Recently, significant improvement in the management of the disease has been demonstrated with long-acting repeatable (LAR) octreotide. This new formulation requires only one monthly intramuscolar injection, and shows better acceptability and patient compliance to therapy. Data available to date show superimposable results of both standard octreotide and LAR octreotide in controlling symptoms, lowering hormone and tumor marker levels, and in reducing tumor growth. The availability of long-acting molecules have permitted the exploration of high-dose therapy in increasing tumor shrinkage and prolonging survival. Although there is a clear dose-response trend, the published data are not conclusive and further investigations are needed. The possible lack of cross-resistance between LAR octreotide and a different analog, Lanreotide, is a very stimulating finding and this might lead to the development of new therapeutical strategies in the management of neuroendocrine tumors.

Regression of metastatic carcinoid tumors with octreotide therapy: two case reports and a review of the literature

BACKGROUND

The antiproliferative effect of the somatostatin analogue, octreotide, on metastatic carcinoid tumors is poorly understood. Partial tumor regression seen radiographically has been reported with the use of octreotide therapy for neuroendocrine tumors. Complete regression of carcinoid tumors is rarely reported.

RESULTS

Two patients with metastatic midgut carcinoid tumors were treated with subcutaneous octreotide 300 microg/day for symptomatic control of their carcinoid syndrome before debulking palliative surgery. During the laporatomies, both patients were found to have complete macroscopic regression of the metastatic lesions that had been identified radiologically before surgery, including liver metastases in one patient and periportal and retrocaval lymph nodes in the other. After surgery, the patients were evaluated every 3 months, and had no detectable disease at 30 and 43 months, respectively. Thirty cases of partial tumor regression with octreotide administered with or without other treatment modalities have been reported in the literature. Most of the patients involved received other treatment modalities. Only one other case reported in the literature showed complete regression with octreotide monotherapy.

CONCLUSIONS

We report two cases of metastatic midgut carcinoid tumors that demonstrated a significant anti-proliferative response to octreotide monotherapy. Review of the literature failed to identify any specific prognostic factors with which the response to octreotide can be predicted. Possible mechanisms for this antiproliferative effect of octreotide on carcinoid tumors are discussed.

Is there a diminishing role for surgery for Merkel cell carcinoma of the skin? a review of current management

Merkel cell carcinoma is a highly malignant skin tumour that must be managed in a multidisciplinary forum. Excisional biopsy of the primary is recommended and this should be followed by postoperative radiotherapy to the primary site, in-transit areas and the draining lymph nodes. The tumour is quite radiosensitive and radiation doses of the order of 50 Gy offer high levels of local control. Resection margins of 3 cm are not required provided postoperative radiotherapy is used. In the event of inoperable disease, patient refusal of surgery or a frail patient, radiotherapy should be used as the sole treatment modality, with high likelihood of achieving local control. Patients with involved nodes have a higher risk of distant disease. Traditionally, involved nodes have been managed with resection but, currently, there are protocols exploring the use of synchronous chemoradiotherapy as definitive treatment. Although adjuvant chemotherapy has been used in this setting to reduce the risk of distant seeding, the benefits at this stage have not been confirmed conclusively. The presence of distant disease carries a grave outlook and responses to chemotherapy occur frequently, but are usually shortlived.

Prospective study of the antitumor efficacy of long-term octreotide treatment in patients with progressive metastatic gastrinoma

BACKGROUND

Malignant pancreatic endocrine tumors (PETs) have a poor prognosis and existing antitumor treatments are unsatisfactory. Recent studies have shown somatostatin analogues to have antitumor growth effects in patients with malignant PETs; however, to the authors' knowledge, little information exists regarding their efficacy or effect on survival in patients with progressive malignant gastrinoma, the most common symptomatic malignant PET. The purpose of the current study was to study prospectively the efficacy, safety, and effect on survival of long-term treatment with octreotide in consecutive patients with progressive malignant gastrinoma.

METHODS

Fifteen consecutive patients with malignant gastrinoma with progressive hepatic metastases were studied. All patients underwent conventional imaging studies (computed tomography scan, magnetic resonance imaging, ultrasound, and, if needed, selective angiography) and somatostatin receptor scintigraphy prior to treatment and at 3-6-month intervals while receiving treatment. The patients all were treated initially with octreotide, 200 microg every 12 hours, and at last follow-up were being maintained on long-acting release octreotide, 20-30 mg every month. Tumor size and/or number were used to classify patient responses as either no tumor response or tumor response (stabilization or decrease in size). Treatment response was correlated with tumor and clinical characteristics.

RESULTS

Tumors in 8 of the 15 patients studied (53%) responded at 3 months, with 47% (7 of 15 patients) demonstrating tumor stabilization and 6% (1 of 15 patients) demonstrating a decrease in tumor size. The mean duration of response was 25.0+/-6.1 months (range, 5.5-54.1 months). Six of the eight responders were continuing to respond at the time of last follow-up. Tumor response did not correlate with any clinical parameter (e.g., tumor extent, fasting gastrin, or acid secretory rates). However, slow-growing tumors were more likely to respond prior to treatment (86% vs. 0%) (P < 0.0014). During follow-up (range, 4-8 years), 25% of the responders died compared with 71% of the nonresponders, a difference that approached statistical significance (P = 0.10). Two patients (13%) developed serious side effects that required the withdrawal of octreotide.

CONCLUSIONS

Octreotide is an effective antitumor treatment in patients with progressive malignant gastrinoma. In approximately 50% of these patients octreotide has an antigrowth effect; treatment is associated with a low incidence of serious side effects compared with other antitumor treatments commonly used and, in contrast to many studies, the growth response is long-lasting. The results of the current study suggest that octreotide treatment should replace chemotherapy as the standard treatment for these patients, especially those patients with slow-growing tumors. Additional studies involving larger numbers of patients will be needed to determine a convincing effect on survival.

Advances in diagnosis and therapy of neuroendocrine tumors

Neuroendocrine tumors represent a group of neoplasias characterized by significant histopathologic and biological heterogeneity. Diagnosis of neuroendocrine tumors relies upon histological examination augmented by newer techniques such as position emission tomography, meta-iodobenzylguanidine scintigraphy or octreoscan. Surgery represents the definite and curative therapeutic approach in early phase tumors. In metastatic or advanced disease, medical treatment is the best choice. Somatostatin analogs allow adequate control of the carcinoid syndrome, without a significant effect on tumor cell growth. Interferon-alpha may represent an alternative, alone or in association with somatostatin analogs. Chemotherapy is the best choice in the treatment of neuroendocrine tumors characterized by a poor differentiation grade and a high proliferation rate.

Phase II trial of dacarbazine (DTIC) in advanced pancreatic islet cell carcinoma. Study of the Eastern Cooperative Oncology Group-E6282

BACKGROUND

A phase II study of dacarbazine (DTIC), was conducted to determine the response rate, duration of response, toxicity and overall survival of patients with advanced pancreatic islet cell tumors.

PATIENTS AND METHODS

Fifty patients with advanced pancreatic islet cell tumors, having progressive symptoms or evidence of rapidly advancing disease were entered on this study. DTIC was given by IV infusion at a dose of 850 mg/m2, over 60-90 minutes, repeated every four weeks.

RESULTS

The response rate was 33% in 42 patients who had measurable tumor, and 34% in the 50 patients (90% confidence interval (90% CI): 23%-47%). The majority of the responses were seen in patients without prior chemotherapy. Median overall survival was 19.3 months. There were two lethal toxicities on the study, one septic shock and one myocardial infarction. Grade 4 toxicities were, hematological (5 patients), sepsis, neurological (depression and paranoid behavior) and bleeding (1 patient each). The most common toxicity was vomiting, grade 3 in 13% of patients.

CONCLUSIONS

DTIC has activity in advanced previously untreated pancreatic islet cell tumors.

Established clinical use of octreotide and lanreotide in oncology

The diagnosis and treatment of neuroendocrine tumors have been significantly improved during the last decades. Localization and staging of the disease by somatostatin receptor scintigraphy (Octreoscan) are now the 'gold standard' for the management of these tumors. Treatment with somatostatin analogs has improved quality of life and possibly also survival for patients with neuroendocrine tumors. New long-acting formulations of the somatostatin analogs are as effective as the old regular formulations but will further improve quality of life for the patients. Tumor-targeted therapy with (111)In and (90)Y coupled to somatostatin analogs show promising results but await further studies.

Octreotide for cancer of the liver and biliary tree

Inoperable liver tumors have an unfavorable natural course despite various therapeutic modalities. Octreotide, a somatostatin analog, has shown considerable antitumor activity on animal models of various hepatic tumors and on isolated cell culture lines. In this paper, a review of the experimental evidence is presented. Moreover clinical papers of case reports of uncontrolled studies of patients are also reviewed. The majority of clinical studies provide evidence of a clinical and biochemical response of liver endocrine tumors while regression of tumor size is a rare event. A randomized controlled trial of octreotide in the treatment of advanced hepatocellular carcinoma has shown a significant survival benefit in the treated patients. Literature reports indicate a stimulatory effect of octreotide on Kupffer cells as a possible antitumor mechanism, but other antiproliferative actions of octreotide have been suggested but not proved. Finally the question of the presence and affinity of somatostatin receptors on liver tumor tissue is discussed. In conclusion, according to our experience, octreotide administration is the best available treatment for advanced inoperable hepatocellular carcinoma and future better patient selection, based on receptor subtypes, might further improve the results.

Different response to the long-acting somatostatin analogues lanreotide and octreotide in a patient with a malignant carcinoid

INTRODUCTION

Somatostatin (SST) analogues are cornerstones in the symptomatic management of patients suffering from carcinoid tumors, and antiproliferative activity has also been reported for these agents. The most commonly applied SST analogues are octreotide (OCT) and lanreotide (LAN), which are both available in a slow release formulation. To the current knowledge, both OCT and LAN are thought to be equally effective for the management of various disorders. We report the case of a patient with a disseminated carcinoid, who progressed during dose-intensified treatment with slow-release LAN in combination with interferon-alpha, but developed a pronounced response after treatment was switched to the application of a depot formulation of OCT.

CASE REPORT

A 46-year-old woman was admitted to our department for the evaluation of persistent flushing, diarrhea and dyspnea. After a diagnosis of metastatic carcinoid had been established, treatment with LAN (30 mg i.m. every 10 days) along with interferon-alpha 3 x 5 MU/week was initiated. In spite of successful blocking of tumoral SST receptors as judged by SST receptor scintigraphy and subjective improvement of symptoms, the patient had progressive disease. As she refused chemotherapy, treatment was switched to a depot formulation of OCT (20 mg i.m. every 4 weeks), resulting both in a disappearance of symptoms as well as tumor regression as seen on CT scanning.

CONCLUSION

To our knowledge, this is the first case demonstrating both a symptomatic as well as objective response to OCT following progression during therapy with LAN in a patient with a carcinoid tumor. Our results suggest that refractoriness to treatment including a long-acting SST analogue does not automatically imply resistance to a related agent and should alert clinicians to the potential of non-cross-resistance between SST analogues in neuroendocrine malignancies.

Radiofrequency ablation treatment of refractory carcinoid hepatic metastases

BACKGROUND

Our institution has experienced excellent success using hepatic artery embolization for treating symptoms and slowing tumor progression for patients with unresectable hepatic metastases for carcinoid tumors. Our previous treatment strategies used hepatic artery embolization alone, examining control of symptoms and dependence on octreotide therapy. However, some patients exhibit hepatic metastases that are unresponsive to embolization. This report describes the use of radiofrequency ablation (RFA) as salvage treatment for these refractory metastases.

METHODS

Thirteen patients with unresectable bilobar hepatic metastases from biochemically confirmed carcinoid tumors were treated with selective hepatic artery embolization using Lipiodol/Gelfoam between 1994 and 2000. Three patients developed symptoms resistant to embolization treatment resulting from progression of existing metastases or development of new metastases. These patients underwent surgical exploration and intraoperative ultrasound of their refractory lesions, followed by treatment with RFA. Tumor size, symptoms of carcinoid syndrome, and octreotide requirements were monitored postoperatively.

RESULTS

Median follow-up for the three patients treated with RFA was 6 months. During the first 3-month interval following RFA, all three patients demonstrated decrease in the size of treated lesions. Using our previously developed symptom scoring system, all three patients demonstrated decreased symptoms following treatment. One patient was able to discontinue octreotide treatment, and the other two patients required decrease octreotide dosages.

CONCLUSIONS

This study demonstrates that utilization of RFA treatment for carcinoid metastases refractory to hepatic artery embolization may represent a useful adjunct for symptomatic control, decreased octreotide dependence, and slowing of disease progression.

Complete histological regression of metastatic carcinoid tumour after treatment with octreotide

A 69-year-old woman was admitted with facial flushing, weight loss and intermittent diarrhoea. Urinary 5-hydroxyindole-acetic acid (5-HIAA) level was elevated at 200 micromol/24 h (normal: < 50). Computerized tomography (CT) demonstrated multiple enhancing liver metastases with biopsy proven carcinoid metastases with no evidence of primary tumour at this stage. Octreotide was initiated, resulting in marked improvement in carcinoid symptoms. Nine years later, she presented with abdominal pain and slightly deranged liver function tests. Repeat colonoscopy at this stage, showed an ileal tumour causing impending obstruction, necessitating urgent right hemicolectomy. Histology demonstrated primary carcinoid tumour. She continued on octreotide. Three years later at the age of 81 years, she suffered a fatal haemorrhagic stroke. Autopsy revealed complete regression of hepatic carcinoid metastases.

The antitumoral effect of the long-acting somatostatin analog lanreotide in neuroendocrine tumors

OBJECTIVE

Somatostatin analogs are the first-line drugs for controlling hormone-mediated symptoms of carcinoid tumors. Prospective and retrospective studies have suggested that somatostatin analogs also have antiproliferative activity. The octapeptide lanreotide is available in sustained-release form, obviating the need for daily injections.

METHODS

A total of 46 patients were enrolled in this open, prospective, phase II trial. They received lanreotide 30 mg i.m. every 14 days for 6 months when they had symptomatic carcinoid tumors, and lanreotide 30 mg i.m. every 10 days if they had nonsymptomatic tumors. Nonsymptomatic tumors were progressive before the start of the study. Tumor size was assessed every 3 months by means of computed tomography. The assessment was centralized and was made by an external panel.

RESULTS

In all, 30 patients had symptomatic neuroendocrine tumors and 16 had asymptomatic neuroendocrine tumors. Five patients in the group with symptomatic tumors and two in the group with nonsymptomatic tumors were considered not to be evaluable. The mean duration of treatment was 12 months in the group with symptomatic tumors and 13 months in the other group. Among the 39 evaluable patients, two objective responses were obtained, giving an objective response rate of 5% (one in the group with symptomatic tumors and one in the other group). Nineteen patients had no significant increase in their tumor size for a mean of 9.5 months.

CONCLUSIONS

Lanreotide is safe and well tolerated in patients with carcinoid tumors. It seems to have both symptomatic and antitumoral effects in this setting.

Treatment of neuroendocrine GEP tumours with somatostatin analogues: a review

BACKGROUND

Somatostatin and its long-acting analogues are effective in symptom control in patients with functionally active neuroendocrine GEP tumours. Several in vitro and in vivo reports suggest that they are also able to control tumour growth.

METHODS

Critical review of published data on the effect of long-acting somatostatin analogues on symptom and growth control in patients with metastatic neuroendocrine GEP tumours.

RESULTS

With the exception of insulinoma and gastrinoma, octreotide acetate and other long-acting somatostatin formulations are currently the therapeutic principle of first choice to control hormone-mediated symptoms. The consequences of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome are best controlled by proton pump inhibitors. Available data on growth control indicate that stabilization of tumour growth seems to be the most beneficial antiproliferative effect occurring in up to 50% of patients. This effect is limited. However, it is unknown which tumour entity responds best to long- acting somatostatin analogues.

CONCLUSION

Additional studies in patients with known spontaneous tumour growth and avoiding a mix-up of different entities of neuroendocrine malignancies are necessary to identify subpopulations of neuroendocrine tumours which respond to long-acting somatostatin analogues in terms of longer lasting growth inhibition.

The role of octreotide in the treatment of gastroenteropancreatic endocrine tumors

Gastrointestinal-endocrine pancreatic (GEP) tumors are rare, occurring in less than 1% of the population. They are usually divided into functionally active or nonfunctioning tumors. Functionally active tumors produce a variety of substances (mainly peptides or serotonin). The tumors are classified according to the dominant clinical syndrome that they cause. Surgery is the treatment of choice in patients with GEP tumors and it should always be considered, even if total tumor excision cannot be achieved. Reduction in tumor mass (debulking) may improve the patients symptoms. Medical treatment is used in patients with advanced malignant endocrine tumors. The most important compounds to control symptoms in these patients are somatostatin analogues. Natural somatostatin is produced in different molecular forms and has inhibitory effects on a number of functions. The observation of potent inhibitory effects on various hormone-secreting cells led to the use of somatostatin for symptomatic treatment of peptide-secreting tumors. Natural somatostatin is not suitable for long-term clinical application; therefore, synthetic somatostatin analogues were developed with improved pharmacokinetic characteristics. The best characterized analogue, octreotide, has been successfully applied to patients with functioning GEP tumors. Octreotide can dramatically ameliorate the debilitating symptoms of patients suffering from the clinical manifestations of endocrine tumors such as diarrhea and flushing. The success of octreotide therapy is best reflected in terms of its impact on the patient's quality of life as defined by the activity to perform normal daily activities.

Scintigraphic imaging of sarcomatous tumors with [(111)In-DTPA-phe-1]-octreotide

The objective of the present study was to investigate the efficacy of (111)In-DTPA-octreotide (OC) for in vivo scintigraphic imaging of these relatively uncommon tumors. Thirteen patients (9 males, 4 females, mean age 59 years) with known sarcomatous lesions were studied. All patients had known lesions as demonstrated by previous investigation with other modalities, e.g. CAT, MRI. Following intravenous injection of 10 microg of OC labeled with 2.8-4.2 mCi (111)In, planar imaging was done at 6 +/- 1 and 22 +/- 2 h, respectively. Histologic verification was obtained in all cases, either from fine needle aspiration or from surgically removed tissue. Positive imaging was observed in 12/13 cases (92.3%). One scan was false-negative (7.7%). Occult lesions were demonstrated in two patients. The histologic typing and the scintigraphy results were: fibrosarcoma (1+/1), embryonic rhabdomyosarcoma (1+/1), leiomyosarcomas (3+/3), liposarcomas (2+/2), uterine sarcomas (2+/2), HIV (-) Kaposi sarcoma (1+/1), osteosarcoma (1+/1), chondrosarcoma (1-/1) and neurogenous sarcoma (1+/1). OC appears to have properties that lead to a new indication for its use. Other possible applications relate to the therapeutic use of octreotide either unlabeled or labeled with a beta-emitting radionuclide, as well as its use in radioimmunoguided surgery. Regarding the latter, our preliminary results are encouraging.

Molecular mechanism of interferon alfa-mediated growth inhibition in human neuroendocrine tumor cells

BACKGROUND & AIMS

Although human neuroendocrine tumors respond to interferon (IFN)-alpha treatment in vivo, the underlying mechanisms of growth inhibition are poorly understood. To characterize the antiproliferative effects at a molecular level, we explored the growth-regulatory action of IFN-alpha in the human neuroendocrine tumor cell lines BON and QGP1.

METHODS

IFN-alpha receptor expression and signal transduction were examined by reverse-transcription polymerase chain reaction, immunoblotting, subcellular fractionation, and transactivation assays. Growth regulation was evaluated by cell numbers, soft agar assays, and cell cycle analysis using flow cytometry. Expression and activity of cell cycle-regulatory molecules were determined by immunoblotting and histone H1-kinase assays.

RESULTS

Both cell lines expressed IFN-alpha receptor mRNA transcripts. Ligand binding initiated phosphorylation of Jak kinases and Stat transcription factors, resulting in Stat activation, nuclear translocation, and transcription from an ISRE-reporter construct. Prolonged IFN-alpha treatment dose-dependently inhibited both anchorage-dependent and -independent growth. Cell cycle analysis of IFN-alpha-treated, unsynchronized cultures revealed an increased S-phase population, which was further substantiated in G(1) synchronized QGP1 cells. IFN-alpha-treated cells entered S phase in parallel to control cultures, but their progress into G(2)/M phase was delayed. Both cellular cyclin B levels and CDC 2 activity were substantially reduced. The extent and time course of this reduction corresponded to the observed S-phase accumulation.

CONCLUSIONS

IFN-alpha directly inhibits growth of human neuroendocrine tumor cells by specifically delaying progression through S phase and into G(2)/M. These cell cycle changes are associated with inhibition of cyclin B expression, resulting in reduced CDC2 activity.

Long-term octreotide treatment of metastatic carcinoid tumor

The optimal dosage of somatostatin analogs for the long-term control of carcinoid tumors has not yet been established. Receptor alterations induced during long term treatment with somatostatin analogs have lead to consecutive drug dosage increases in order to control carcinoid disease. In this report, we describe the rapid and effective control of tumor in a patient with metastatic carcinoid treated for nine years with a single daily dose of octreotide based on tumor marker levels. Tumoral somatostatin receptor (sst) subtype analysis by RT-PCR amplification showed the expression of sst2 subtype only. We suggest that a single daily dose of octreotide strictly related to tumor marker secretion, could have played a role in the effective long-term therapy by avoiding the phenomenon of somatostatin receptor desensitisation. Furthermore, the exclusive presence of sst2 subtype supports the high affinity of octreotide to tumoral cells.

Neuroendocrine pancreatic cancer: an unusual case of pancreatitis

Acute pancreatitis is a common clinical problem. This case of acute pancreatitis was due to a most uncommon underlying aetiology, a non-functioning neuroendocrine tumour of the pancreas.

Local recurrence after laparoscopic radiofrequency thermal ablation of hepatic tumors

BACKGROUND

Since we first described laparoscopic radiofrequency ablation (LRFA) of liver tumors, several reports have documented technical and safety aspects of this procedure. Little is known, however, about the long-term follow-up of such patients.

METHODS

From January 1996 to February 1999, we performed LRFA on 250 liver tumors in 66 patients. Triphasic spiral computed tomographic scanning was obtained preoperatively and at 1 week, and every 3 months postoperatively. Lesion diameter was measured in the x- and y-axes and the volume estimated; 181 lesions in 43 patients for whom computed tomographic scans available were included in the study. The tumor types were as follows: 64 metastatic adenocarcinomas, 79 neuroendocrine metastases, 27 other metastases, and 11 primary liver tumors.

RESULTS

One week postoperatively, the ablated zone was larger than the original tumor in 178 of 181 lesions, which suggests ablation of the tumor and a margin of normal liver tissue. A progressive decline in lesion size was seen in 156 (88%) of 178 lesions, followed for at least 3 months (mean, 13.9 months; range, 4.9-37.8 months), which suggests resorption of the ablated tissue. Fourteen definite local treatment failures were apparent by increase in size and change in computed tomographic scan appearance, and eight lesions were scored as failures because of multifocal recurrence that encroached on ablated foci (22 total recurrences). Predictors of failure include lack of increased lesion size at 1 week (2 of 3 such lesions failed), adenocarcinoma or sarcoma (18 of 22 failures; P < .05), larger tumors (failures, M = 18 cm3 vs. successes, M = 7 cm3; P < .005) and vascular invasion on laparoscopic ultrasonography. By size criteria, 17 of 22 failures were apparent by 6 months. Energy delivered per gram of tissue was not significantly different (P = .45).

CONCLUSIONS

LRFA has a 12% local failure rate, with larger adenocarcinomas and sarcomas at greatest risk. Failures occur early in follow-up, with most occurring by 6 months. LRFA seems to be a safe and effective treatment technique for patients with primary and metastatic liver malignancies.

Uptake of radiolabeled somatostatin analog is detectable in patients with metastatic foci of sarcoma

BACKGROUND

Somatostatin receptors are present on many types of epithelial tumors, and ligands targeting these receptors are used to treat patients with neuroendocrine malignancies. Preclinical studies have demonstrated the presence of somatostatin receptors on a variety of mesenchymal tumors by in vitro receptor autoradiography. The use of radiolabeled somatostatin analogs to assess the presence of somatostatin receptors in vivo has been established, but use of this technique to evaluate human sarcomas has not been reported previously.

METHODS

Seventeen patients (13 females and 4 males) with metastatic sarcoma underwent imaging via somatostatin-receptor scintigraphy. Scans were performed using indium -111 pentetreotide. Planar studies and single photon emission computed tomography imaging were performed at 4 and 24 hours, and results of scintigraphy were correlated with computed tomography findings.

RESULTS

Twelve of 17 scans showed increased uptake in regions of known metastatic disease. There was no apparent correlation with scan positivity and patient age, histology, site of disease, or duration of diagnosis.

CONCLUSIONS

Seventy-one percent of patients with advanced soft-tissue sarcomas had positive scintigraphy scans demonstrating tumor expression of somatostatin receptors subtype 2 in vivo. Imaging with indium-111 pentetreotide could be studied as an adjunct to conventional imaging modalities for assessment of sarcoma patients. Further research is needed to determine the prognostic implications of somatostatin receptor subtype 2 positivity, including larger studies to evaluate any potential correlation with metastatic behavior and other clinical outcomes.

Combination therapy with octreotide and alpha-interferon: effect on tumor growth in metastatic endocrine gastroenteropancreatic tumors

OBJECTIVE

We investigated the antiproliferative efficacy of the addition of alpha-interferon to the somatostatin analogue octreotide in patients with metastasized gastroenteropancreatic tumors unresponsive to octreotide monotherapy.

METHODS

In an open prospective trial, 21 patients with metastasized neuroendocrine gastroenteropancreatic tumors (nine patients with carcinoid syndrome, eight with nonfunctioning tumors, four with gastrinoma) were treated with 5 x 10(6) IU alpha-interferon tiw in addition to 200 microg of octreotide tid. All patients, including 16 patients with preceding monotherapy with 200 microg of octreotide tid, had tumor progression documented by computed tomography before entering the study. Growth response (computed tomography documented) and biochemical response were assessed at 3-month intervals.

RESULTS

Inhibition of tumor growth was observed in 14 patients (67%), 11 of whom had preceding octreotide monotherapy; complete regression was observed in one patient lasting for 49 months and stable disease (stand-still) in 13 patients lasting for 3 to 52 months (median, 12 months). Seven patients failing this combination therapy exhibited a significantly shorter overall survival (median, 23 months; range, 5 to 42 months) than the 14 patients responding to this regimen (median, 68 months; range, 12 to 112 months; p = 0.007). Two patients are still alive. Biochemical response was achieved in 69% of patients with functioning tumors: in three of four patients with gastrinoma and in six of nine patients with carcinoid syndrome.

CONCLUSIONS

These data suggest that the addition of alpha-interferon to octreotide has antiproliferative efficacy in a subgroup of patients with advanced metastatic disease unresponsive to octreotide monotherapy. Prolonged survival was seen in the responder group.

Recent advances in systemic therapy for gastrointestinal neuroendocrine tumors

Neuroendocrine tumors of the gastrointestinal tract are rare tumors which can be classified as amine precursor uptake and decarboxylation tumors (APU-Domas). Although the majority of clinically apparent tumors are malignant, they are frequently slow growing. Despite this characteristic, they may generate disabling hormonal syndromes requiring aggressive treatment to achieve palliation. Recent advances in understanding the pathophysiology of these tumors has led to better medical therapy with chemotherapeutic agents, somatostatin analogues, and biologic therapies. This review will update the recent efforts in systemic therapies of the gastrointestinal neuroendocrine tumors.

Octreotide induced remission of a refractory small cell carcinoma of the endometrium

This is the first report of remission obtained with octreotide in a woman diagnosed with recurrent small cell carcinoma of the endometrium with neuroendocrine features, refractory to a combination of etoposide, cisplatin, and radiation therapy. Stabilization of disease was obtained with a combination of tamoxifen and leuprolide depot. Regression of disease was then achieved by the addition of octreotide. The use of octreotide as an antitumor agent is reviewed.

Carcinoid tumour

Carcinoid tumours are often indolent asymptomatic tumours. However, a small but significant proportion are malignant and difficult to manage. Multiple endocrine neoplasia type 1 (MEN-1) may be associated with carcinoid tumours and should therefore be considered in the investigation of these patients. This review puts into context the use of newer imaging modalities, including octreotide scintigraphy. The therapeutic treatment options are discussed, including the use of octreotide, the role of receptor-targeted therapy, hepatic-artery embolisation, and the arguments against chemotherapy. We review the need for careful patient selection when considering curative and palliative surgery, including liver transplantation. We conclude that there are now better diagnostic tools and therapeutic options available for those patients with malignant carcinoid tumours, and that these patients are best managed by a multidisciplinary approach. Earlier detection and treatment of these tumours should lead to improved quality of life and survival, which, ideally, should be assessed in formal trials.

5-Fluorouracil, dacarbazine, and epirubicin in the treatment of patients with neuroendocrine tumors

BACKGROUND

For patients with surgically untreatable neuroendocrine tumors (NETs), the optimal therapeutic approach remains undefined. Somatostatin analogs and interferons have failed to control neoplastic growth, and chemotherapy has been only moderately more effective. The authors' previous study of the combination of 5-fluorouracil (FU), dacarbazine (DTIC), and epirubicin (EPI) (the FDE regimen) documented good tolerability, but the results for tumor growth control were disappointing. In an attempt to improve these results, the authors conducted a preliminary trial of an intensified FDE regimen (FU 500 mg/m2 administered intravenously [i.v.], DTIC 200 mg/m2 i.v., and EPI 30 mg/m2 i.v. on Days 1, 2, and 3 every 3 weeks).

METHODS

Thirty NET patients (15 male, 15 female; median age, 55 years; age range, 19-72 years) were enrolled, none of whom had previously been given chemotherapy. The histologic types of disease were gastroenteropancreatic (GEP) tumors (n = 21, 6 carcinoid tumors and 15 pancreatic NETs), other carcinoid tumors (n = 3), other NETs (n = 4), medullary thyroid carcinoma (MTC) (n = 1), and Merkel cell carcinoma (n = 1). Six patients had a syndrome related to endocrine hypersecretion. One hundred fifty-four therapy cycles were delivered (median, six per patient), and all patients could be evaluated for response on the basis of intent-to-treat analysis.

RESULTS

There were 9 objective responses: 2 complete responses (in 1 patient with Merkel cell carcinoma and 1 with pancreatic NET) and 7 partial responses (in 3 patients with pancreatic NETs, 2 with other NETs, 1 with GEP carcinoid tumor, and 1 with MTC). The median duration of response was 10 months (range, 5+ to 24+ months). No reduction in symptoms was achieved among the six patients with endocrine hypersecretion syndrome. Levels of urinary 5-hydroxyindoleacetic acid and serum chromogranin A were decreased in 50% and 14% of patients, respectively, who presented with abnormal baseline values. Treatment toxicity was acceptable and included nausea and vomiting, alopecia, leukopenia, and mucositis.

CONCLUSIONS

This trial demonstrated that the FDE regimen may be at least as effective as other systemic regimens. Comparison of this experience with the authors' previous trial revealed a noteworthy increase in the activity of the intensified regimen, especially in GEP NETs (the most chemoresistant tumors). Continued clinical research to improve these results is highly justified.

Chemotherapy for neuroendocrine tumors: the Beatson Oncology Centre experience

The role of chemotherapy in malignant neuroendocrine tumours is difficult to assess because of their rarity and variation in biological behaviour. We present a retrospective review of chemotherapy given to 18 patients with metastatic and one with locally advanced neuroendocrine tumours. There were eight poorly differentiated neuroendocrine tumours, six thyroid medullary carcinomas, two phaeochromocytomas, two pancreatic islet cell tumours and one undifferentiated neuroblastoma. Four patients were given 3-weekly dacarbazine, vincristine and cyclophosphamide (DOC) chemotherapy. In eight patients, this regimen was modified by substituting the dacarbazine and cisplatin and etoposide (OPEC). A further six patients were treated with dacarbazine reintroduced into the 3-weekly regimen (DOPEC). The remaining patient received cisplatin and etoposide. There were two complete responses (both with OPEC) and eight partial responses (two with DOC, three with OPEC and three with DOPEC). Five patients had stable disease and four progressed. Four received further chemotherapy on relapse, producing one complete and one partial response. The median response duration to initial chemotherapy was 10 months (range 3-34). The median survival was 12 months (range 1-42). The main toxicity was haematological, with grade 3-4 neutropenia in 12 patients; eight suffered episodes of sepsis. One death was treatment related. Other toxicity was mild although three patients discontinued vincristine with grade 2 neurotoxicity. The response rate and side effects of these three regimens appear comparable. We conclude that, although these patient numbers are small, combination chemotherapy produces an encouraging response rate (53%; 95% CI 30-75) in malignant neuroendocrine tumours, with acceptable toxicity.

Laparoscopic thermal ablation of hepatic neuroendocrine tumor metastases

BACKGROUND

Neuroendocrine tumor metastases to the liver are generally slow growing, but patients suffer from hormone hypersecretion despite aggressive multimodality therapy. A minimally invasive method of tumor ablation affords symptomatic improvement with minimal morbidity.

METHODS

Radiofrequency electrical energy is delivered to tissues via a 4-prong catheter resulting in tissue heating to 60 to 70 degrees C and cell death. Porcine studies were conducted to define appropriate parameters for energy delivery and then applied to patients using laparoscopic techniques.

RESULTS

In the porcine model 3.5 to 4 cm lesions were reproducibly created in 15 minutes using 30 to 50 W of power. The ablation process was monitored via temperature feedback from thermocouples in the catheter tips and by a hyperechoic blush noted on ultrasonography. Laparoscopic thermal ablation of 13 tumors in six patients with carcinoid (two patients), gastrinoma, insulinoma, nonsecreting islet cell cancer, or medullary thyroid cancer was performed. There were no intraoperative complications, and all patients were discharged the next day. Successful ablation was confirmed by spiral-computed tomography and by symptomatic improvement in patients with secreting tumors.

CONCLUSIONS

Laparoscopic thermal ablation of hepatic tumors is a novel, minimally invasive method of providing effective cytoreduction of neuroendocrine tumors metastatic to the liver.

Uptake of In-111 pentetreotide by normally functioning nodular goiters

After the intravenous administration of a radiolabeled somatostatin analogue (octreotide), normal thyroid and neoplastic and nonneoplastic thyroid lesions can be visualized. The authors present the cases of two patients who underwent somatostatin receptor scintigraphy (SSRS) using In-111 pentetreotide: one for the study of suspected paraneoplastic ACTH hypersecretion, and the other for a restaging of breast carcinoma with neuroendocrine features. In both patients, SSRS revealed increased uptake in the thyroid, corresponding to "cold" nodules on Tc-99m pertechnetate imaging. Cytologic and histologic examinations showed the typical features of thyroid goiters without lymphocytic infiltration.

[Merkel cell carcinoma: primary cutaneous neuroendocrine tumor]

Merkel cell carcinoma is a neuroendocrine primitive tumor of the skin. We report a case who develops node and visceral metastasis, and dead. The clinical presentation, diagnosis, histology, immunocytochemistry, treatment and prognosis of this tumor will be discussed.