Summing up 15 years of somatostatin analog therapy in neuroendocrine tumors: future outlook

Elevated fibroblast growth factor-23 in hypophosphatemic linear nevus sebaceous syndrome

We report on an adolescent who experienced the onset of linear nevus sebaceous syndrome (LNSS) prior to 1 year of age. At 7 years of age he was diagnosed to have hypophosphatemic rickets. He was suboptimally controlled with phosphate and calcitriol treatment and sustained numerous insufficiency fractures ipsilateral to the linear sebaceous nevus. Fibroblast growth factor-23 (FGF-23), the phosphaturic peptide, was elevated in the plasma. Treamtent with the somatostatin agonist, octreotide, and excision of the nevus were followed by normalization of FGF-23 and clinical improvement. The patient also had hyperimmunoglobulinemia E, which responded to octreotide and surgery. We speculate that in some patients with LNSS there may be more than one mediator of hypophosphatemia and that FGF-23 is the mediator of hyperphosphaturia in this and other hypophosphatemic syndromes.

Poorly differentiated small cell carcinoma of the pancreas. A case report and review of the literature

Small cell carcinoma (SCC) of the pancreas is a rare malignancy with an extremely poor prognosis. We present the case of a 74-year-old man with a 2-month history of upper abdominal discomfort who was diagnosed with SCC of the pancreas tail, involvement of peripancreatic and mesenteric lymph nodes and multiple liver metastases (extended disease). A CT scan and a positive somatostatin receptor scintigraphy showed no evidence of a primary lung tumour. The diagnosis of a SCC was confirmed by biopsy. Local tumour control could be achieved by gemcitabine once a week and a long-acting somatostatin analogue once a month, but liver metastasis showed progress. Thus, 5-fluorouracil on a weekly basis was started. The patient died 8 months after diagnosis and had not been hospitalised in the meantime.

Cellular proliferative fraction measured with topoisomerase IIalpha predicts malignancy in endocrine pancreatic tumors

CONTEXT

Endocrine pancreatic tumors (EPTs) are rare lesions with varying biological behavior. Establishing malignancy is a challenge for clinicians and pathologists.

OBJECTIVE

To establish the role of proliferative, apoptotic, angiogenic, and hormonal markers as predictors of malignancy in EPTs.

DESIGN

Paraffin-embedded EPT samples were studied for prognostic markers.

PATIENTS

Twenty-one consecutive patients with a diagnosis of EPT.

MAIN OUTCOME MEASURES

The proliferative fraction (topoisomerase IIalpha), microvascular density (CD34), vascular endothelial growth factor expression, and estrogen receptor-beta (ERbeta) expression were studied by immunohistochemistry on all EPTs. Apoptosis was also assessed with terminal deoxynucleotidyl transferase nick-end labeling.

RESULTS

We identified 13 benign and 8 malignant tumors. Topoisomerase IIalpha was significantly increased in malignant tumors (P =.001), while there were no differences in apoptosis, microvascular density, or vascular endothelial growth factor expression in association with malignancy. No correlation could be identified between microvascular density and vascular endothelial growth factor expression, and ERbeta was not detected. A receiver operating characteristic curve for topoisomerase IIalpha disclosed that above a labeling index of 13, the test had 88% sensitivity and 100% specificity for predicting malignancy.

CONCLUSION

Cellular proliferation measured with topoisomerase IIalpha is a simple prognostic marker for malignancy in EPTs, unlike apoptosis, angiogenesis, or the presence of ERbeta, which were not associated with malignant behavior. These findings designate a defined field for future research on endocrine pancreatic carcinogenesis and a possible target for chemotherapeutic agents.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Cancer imaging - making the most of your gamma camera

As MRI threatens the use of bone scintigraphy for skeletal metastases and 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) emerges as the main focus in nuclear oncology, the future role of the gamma camera in cancer imaging appears unclear. However, there is a range of pre-existing conventional gamma camera techniques that have incremental benefit over CT and other structural imaging techniques, but are yet to be fully exploited in the care of cancer patients. This article reviews some of the more advanced conventional nuclear medicine techniques for cancer imaging. Often gamma camera techniques perform close to 18FDG - PET or provide complementary information.Where 18FDG - PET is diagnostically superior, the incremental cost-effectiveness gain of 18FDG - PET over conventional gamma camera techniques has not always been fully evaluated.

A cyclic peptide, L1AD3, induces early signs of apoptosis in human leukemic T-cell lines

L1AD3 is a small cyclic synthetic peptide designed to resemble the first loop of a cobra venom cytotoxin. Instead of inducing membrane disruption similar to that caused by the parent toxin, L1AD3 promotes extensive and unusually rapid apoptosis in leukemic T-cells without making the plasma membrane permeable to small fluorescent dyes. Within 4 h, micromolar concentrations of L1AD3 almost totally inhibit thymidine incorporation, and ATP levels decrease significantly. By contrast, normal human white blood cells are not affected by L1AD3, nor is heart cell function affected by it. If L1AD3 kills by interacting with targets that are different from those of currently applied agents, this peptide, or a derivative of it, could become a useful adjunct for cancer chemotherapy.

[Bone scintigraphy and somatostatin receptor scintigraphy in pediatric patients with bone involvement in Langerhans cell histiocytosis]

Langerhans cell histiocytosis (LCH) is a granulomatous disease which can involve multiples sites of the body. Diagnostic imaging is of utmost importance in the management of these patients. Up to now radiographic skeletal survey and bone scintigraphy (BS) have been used to assess bone involvement (both with low specificity). Magnetic resonance imaging (MRI) and CT have been used to assess visceral involvement but with the limitation that they cannot give information about the functional status. Recently somatostatin receptor scintigraphy (SSRS) has been proposed to detect active lesions and to monitor response to treatment. The aim of this study is to assess bone and somatostatin receptor scintigraphy in the detection of bone involvement in LCH in children. Twenty scintigraphies (12 SSRS and 8 BS) were performed in seven patients (3 girls and 4 boys) aged at diagnosis: 18 month-12 years (mean age 6 years). The findings obtained in the scintigraphies were compared with clinical evolution and other imaging techniques. Bone scintigraphy detected all the LCH bone lesions, and discovered one unknown lesion. SSRS scintigraphy visualised the active lesions in 3 patients (clinical and other imaging techniques were also positive). SSRS was negative in one patient classified as disease free and another in clinical remission. SSRS detected 2 new unknown bone lesions, but could not detect LCH bone lesions confirmed in other imaging techniques in 2 patients. Somatostatin receptor and Bone scintigraphy can be used to detect active LCH bone lesions in children and can help to monitor response to treatment. Further studies with more patients are needed to confirm the diagnostic usefulness of these techniques.

Randomized clinical trial of the effect of interferon alpha on survival in patients with disseminated midgut carcinoid tumours

BACKGROUND

Midgut carcinoid tumours often present with widespread disease making curative surgery impossible. Medical treatment therefore plays a major role in the treatment of these patients.

METHODS

In this prospective randomized study, the effect of interferon (IFN) alpha on survival and risk of tumour progression was evaluated in 68 patients with midgut carcinoid tumours metastatic to the liver. All patients had undergone primary surgical treatment and hepatic arterial embolization of liver metastases before randomization. Patients were randomized to treatment with either octreotide alone (n = 35) or octreotide in combination with IFN-alpha (n = 33).

RESULTS

Forty-one of the 68 patients died during a follow-up period of 33-120 months, equivalent to a 5-year survival rate of 46.5 per cent. There was no significant difference in survival between patients treated with octreotide alone (5-year survival rate 36.6 per cent) and those given octreotide in combination with IFN-alpha (56.8 per cent). However, patients treated with IFN-alpha had a significantly reduced risk of tumour progression during follow-up (P = 0.008).

CONCLUSION

Addition of IFN-alpha to octreotide may retard tumour growth in patients with midgut carcinoid tumours.

Distress, quality of life and strategies to 'keep a good mood' in patients with carcinoid tumours: patient and staff perceptions

Patients with carcinoid tumours have reported a relatively good health-related quality of life (HRQoL) (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30, EORTC QLQ-C30), and low levels of anxiety and depression (Hospital Anxiety and Depression Scale, HADS). The aim was to test the validity of these results. Data were gathered through interviews with 19 patients and 19 staff. Participants were asked about disease and treatment related distress, important aspects of quality of life and strategies to 'keep a good mood'. Patients were interviewed about themselves and staff were interviewed about a certain patient. Data were analysed by content analysis. Identified aspects of distress and quality of life were referred to an emotional, a physical and a social dimension. Most aspects of distress were of a physical character whereas most aspects of quality of life were of a social character. Several aspects of emotional distress not included in the EORTC QLQ-C30 and/or the HADS were identified.

Somatostatin analogs and radiopeptides in cancer therapy

Since the discovery of somatostatin (sst) in 1973, numerous chemical and biological studies have been carried out to develop sst analogs with enhanced resistance to proteases and prolonged activity. Three highly potent sst analogs-octreotide, lanreotide, and vapreotide-are now available in the clinic, and demonstrate efficacy in the treatment of tumors of the pituitary and the gastroenteropancreatic tract. The most striking effect is the control of hormone hypersecretion associated with these tumors. Available data on growth suppression in patients indicate a limited antiproliferative action, tumor shrinkage is observed in 10-20% patients, and tumor stabilization in about half of the patients for duration of 8-16 months. Eventually, however, all patients escape from sst analog therapy with regard to both hormone hypersecretion and tumor growth, the only exception being observed in acromegalic patients who do not experience tachyphylaxis even after more than 10 years of daily octreotide injection. The mechanism underlying the escape phenomenon is not yet clarified. Regarding the molecular mechanisms involved in sst antineoplastic activity, both indirect and direct effects via specific somatostatin receptors (SSTRs) expressed in the target cells have be described. Direct action may result from blockade of mitogenic growth signal or induction of apoptosis following interaction with SSTRs. Indirect effects may be the result of reduced or inhibited secretion of growth-promoting hormones and growth factors that stimulate the growth of various types of cancer; also, inhibition of angiogenesis or influence on the immune system are important factors. Five SSTR subtypes have been identified so far, which are variably expressed in a variety of tumors such as gastroenteropancreatic (GEP) tumors, pituitary tumors, and carcinoid tumors. Although all five SSTR subtypes are linked to adenylate cyclase, they are now known to affect multiple other cellular signaling systems and hence they differentially participate in the regulation of the various cellular processes. The finding of several laboratories that SSTR-expressing tumors frequently contain two or more SSTR subtypes, and the recent discovery that SSTR subtypes might form homo/heterodimers to create a novel receptor with different functional characteristics, expand the array of selective SSTR activation pathways and subsequent intracellular signaling cascades. This may lead to improved clinical protocols that take into account possible synergistic interactions between the SSTR subtypes present on the same cancer cell. Radiolabeled sst analogs, such as [(111)In]-[diethylenetriamine pentaacetic acid (DTPA)-D-Phe(1)]-octreotide (OcreoScan), have proved to be very useful for tumor scintigraphy and internal radiotherapy of SSTR overexpressing tumors. The recent introduction of the metal chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) considerably improved the stability of the radioconjugates, making possible the incorporation of a variety of radionuclides, such as (90)Y for receptor-mediated radionuclide therapy or (68)Ga for positron emission tomography (PET). Another promising area is the development of sst conjugates incorporating cytotoxic anticancer drugs.

Carcinoid tumors

Carcinoids are rare endocrine tumors that can develop in several organs in the body. Clinically, patients can have a wide spectrum of signs and symptoms that range from incidental findings of a polyp during endoscopy to the carcinoid syndrome characterized by severe flushing, diarrhea, abdominal cramping, and life-threatening right-sided heart failure. Most carcinoid tumors are indolent but can metastasize to regional lymph nodes and to other organs, including the liver, bone, and the central nervous system. Treatment is determined by tumor location and by the presence of distant metastasis. Surgical resection of the tumor is advocated in patients with localized disease and can often be curative. Long-acting somatostatin analogs, including octreotide, octreotide long-acting repeatable, and lanreotide prolonged release, are effective in providing symptom relief in patients with the carcinoid syndrome. Patients with metastatic disease to the liver that is refractory to somatostatin treatment should be considered for hepatic artery occlusion. Overall, 5- and 10-year survival rates in patients with metastatic disease are favorable, although tumors can be resistant to most forms of medical or surgical therapy.

Treatment of advanced neuroendocrine tumours using combination chemotherapy with lomustine and 5-fluorouracil

OBJECTIVE

Combination chemotherapy with the two agents streptozotocin (SZT), which is a nitrosurea, and 5-fluorouracil (5-FU), an alkylating agent, has a long-established role in the treatment of neuroendocrine tumours; however, it is often accompanied by considerable toxicity, and it has not been assessed in a comparative manner with other current chemotherapy regimens. In order to assess the therapeutic response and adverse effects using an alternative nitrosurea, lomustine (CCNU), which has a different side-effect profile, in combination with 5-FU, we have reviewed all patients with neuroendocrine tumours who received this form of treatment in our department.

DESIGN

Retrospective analysis of the case notes of patients with metastatic neuroendocrine tumours who received treatment with the combination of CCNU and 5-FU, and who were followed up according to a defined protocol in a given time frame.

PATIENTS

Thirty-one patients with metastatic neuroendocrine tumours (18 with carcinoid tumours, five islet-cell tumours, five chromaffin-cell tumours and three medullary carcinoma of the thyroid) treated with the combination of CCNU and 5-FU, and when necessary additional therapy, over a 22-year period, were included in this analysis.

MEASUREMENTS

The symptomatic, hormonal and tumoural responses before and after chemotherapy with the combination of CCNU and 5-FU over a median follow-up duration of 25 months (range 9-348 months) were recorded. Of the 31 patients (16 males; median age 52 years, range 20-86 years), eight (four males; median age 61 years, range 30-74 years) were treated with the combination of CCNU and 5-FU alone (Group 1), whereas the other 23 patients (12 males; median age 47 years, range 20-86 years) received additional therapy with other chemotherapeutic regimens, somatostatin analogues, alpha-interferon or radiolabelled meta-iodobenzylguanidine (131I-MIBG) therapy (Group 2).

RESULTS

A total of 121 therapeutic cycles was administered (mean 3.9, range 1-14 cycles). None of the patients obtained a complete tumour response. A partial tumour response (not a complete but a 50% or greater reduction of all measurable tumour) was seen in six out of the 29 patients (21%) (four out of eight in Group 1 and two out of 21 in Group 2, respectively). There was no tumour progression in eight out of the 29 patients (27.5%) (one out of eight in Group 1 and seven out of 21 in Group 2, respectively). The median survival over the period of the study was 48 months (95% confidence interval, CI, 22-74 months). The overall 5-year survival rate was 42% (95% CI, 17-67%) for all patients and 50% (95% CI, 18-83%) for the carcinoid group alone, according to Kaplan-Meier analysis. A complete or partial symptomatic response was obtained in 12 out of 27 (44%) patients who presented with symptoms (four out of eight in Group 1 and eight out 19 in Group 2, respectively) and a complete or partial hormonal response in eight out of 19 patients (42.1%) who presented with hormonally active disease (two out of four in Group 1 and six out of 15 in Group 2, respectively). Nine out of the 15 (60%) patients with carcinoid tumours who presented with symptoms obtained a symptomatic response, five out of 10 patients (50%) a hormonal response, and four out of 16 (25%) patients a partial tumoural response, respectively. The combination of CCNU and 5-FU was safe and well tolerated. Serious side-effects necessitating the termination of CCNU and 5-FU were seen only in two patients, and mainly consisted of reversible bone marrow suppression. No chemotherapy-related death was recorded.

CONCLUSIONS

Chemotherapy with CCNU and 5-FU, either alone or in combination with other therapeutic modalities, produces considerable symptomatic and hormonal improvement and moderate tumour regression/stabilization according to currently accepted WHO criteria, particularly in patients with metastatic gastroenteropancreatic neuroendocrine tumours with minimal adverse effects. However, long-term survival was still relatively poor. It may therefore be a valuable additional therapl was still relatively poor. It may therefore be a valuable additional therapeutic option, particularly for well-differentiated carcinoid and islet-cell tumours, but mainly reserved for when there is no response or progression of the disease after currently available first-line treatment with somatostatin analogues or radiopharmaceuticals.

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.

Functional imaging of Langerhans cell histiocytosis by (111)In-DTPA-D-Phe(1)-octreotide scintigraphy

BACKGROUND

Langerhans cell histiocytosis is a rare group of diseases of unknown pathogenesis, variable clinical presentation, and behavior. It encompasses highly aggressive, often fatal, and indolent diseases, with a variety of intermediate forms between the two extremes. Localization and monitoring of Langerhans cell histiocytosis deposits are based on the combined use of different imaging modalities, which include magnetic resonance, computed tomography, and nuclear medicine procedures. Somatostatin receptor scintigraphy recently has been used to image immune-mediated diseases with excellent results.

METHODS

In this study, the authors have evaluated the potential role of somatostatin receptor scintigraphy by using (111)In-DTPA-D-Phe(1)-octreotide in a series of patients with Langerhans cell histiocytosis. Eight consecutive patients (2 males, 6 females; mean age, 43 years; age range, 29-60 years) with histologically proven Langerhans cell histiocytosis, in various phases of their disease, were imaged 24 hours after intravenous injection of 111-222 MBq of (111)In-DTPA-D-Phe(1)-octreotide, by using total body and spot view images. The objective of the study was to preliminarily evaluate this technique in the evaluation of Langerhans cell histiocytosis.

RESULTS

Most Langerhans cell histiocytosis deposits were clearly documented by somatostatin receptor scintigraphy, independently from the anatomic location (i.e., skeleton, mucosae, soft tissue, etc.). The correlation between conventional imaging modalities and somatostatin receptor scintigraphy results was fairly good, though this was not considered a primary objective of the study.

CONCLUSIONS

Among the various imaging modalities for Langerhans cell histiocytosis, somatostatin receptor scintigraphy is unique, because it accurately depicts the active sites of disease and thus can help in monitoring the response to treatment, together with conventional imaging modalities. Further studies are necessary to confirm the diagnostic value of this technique and clarify the biologic significance of the expression of somatostatin receptors in Langerhans cell histiocytosis.

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.

Radioisotope diagnosis and therapy of malignant pheochromocytoma

The availability of radiopharmaceuticals to depict primary malignant pheochromocytoma and its metastases has markedly changed the approach to these unusual cancers. Whole body screening afforded by scintigraphy allows remote tumor involvement to be identified and provides staging information necessary to guide subsequent therapy. The avid accumulation by malignant pheochromocytoma of some radiopharmaceuticals used for scanning has shown promise in therapeutic trials. In this paper, we discuss radiopharmaceuticals presently employed in malignant pheochromocytoma for both diagnostic and therapeutic uses and potential future compounds that may find their way into clinical practice in the approach to these and other related neoplasms.

Treatment of gastroenteropancreatic neuroendocrine tumours with octreotide LAR

BACKGROUND

Octreotide long acting repeteable (LAR) is a new somatostatin analogue whose activity lasts 28 days.

AIM

To assess its therapeutic efficacy, tolerability, and safety in patients with gastroenteropancreatic neuroendocrine tumours.

METHODS

A total of 16 patients were studied; 10 patients with carcinoid tumours, three with non-functioning pancreatic tumours, two with Zollinger-Ellison syndrome associated with multiple endocrine neoplasia type 1, and one with glucagonoma were studied. Octreotide LAR was administered intramuscularly at a dose of 20 mg every 28 days for a mean of 10.7 months (range 6-15 months).

RESULTS

In carcinoid tumour patients, octreotide LAR normalized bowel movements in nine out of 10 cases, and flushing episodes disappeared in seven out of eight cases. Even in the remaining six patients the symptoms disappeared. In carcinoid tumour patients, urinary 5-hydroxyindoleacetic acid decreased significantly. In the two patients with Zollinger-Ellison syndrome/multiple endocrine neoplasma type 1 and in the patient with glucagonoma, serum gastrin and plasma glucagon, respectively, decreased considerably. Tumour size remained unchanged in 14 out of 16 patients, and increased in the remaining two. No side-effects were observed.

CONCLUSIONS

Octreotide LAR appears to have a good therapeutic efficacy, tolerability and safety in the treatment of neuroendocrine tumours. Its effects are similar to those of octreotide and lanreotide. However, because it only needs to be administered once every 28 days, it is preferable in clinical practice.