Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuroendocrine tumors (NET) of the gastrointestinal tract are rare and constitute 0.5-1% of all human malignancies. Based on their endocrine secretion, they are functional active or inactive. They are further classified into fore-, mid-, or hindgut tumors. The recently published WHO-classification grouped the tumors according to their tumor size, angioinvasion and Ki-67 index. NET are mainly diagnosed in an advanced tumor stadium because of the paucity of symptoms or when symptoms occur due to endocrine hypersecretion. NET are diagnosed serologically by their hormone secretion and by measuring Chromogranin A levels. They are further detected by CT, MRI or endoscopy including endoscopic ultrasound. Many NET have somatostatin receptors on their surface and can be diagnosed by somatostatin receptor scintigrafy with high sensitivity and specificity. Only by surgery NET can be cured. Because many tumors are diagnosed late, medical options are of utmost importance. Symptom control can be established by somatostatin analogues and interferon-ot. Diazoxid can further inhibit insulin secretion, proton pump inhibitors are the therapy of choice for acid hypersecretion in Zollinger-Ellison syndrome. Advanced neuroendocrine cancers can be treated with chemotherapy. Recently, radio receptor therapy with 90Y-DOTA Octreotid and 177Lu-DOTA Octreotate was established in advanced neuroendocrine cancers and is further evaluated in studies. Net of the gastrointestinal tract should be treated in a multidisciplinary approach with gastroenterologists, surgeons and experts in nuclear medicine. An overview about epidemiology, clinical features, diagnostic methods and therapy of NET of the gastrointestinal tract will is provided in this article.
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PMID:[Neuroendocrine tumors of the gastrointestinal tract]. 1725 57

Coexistence of pituitary adenoma, intracranial meningioma and cerebral aneurysm has never been described. We report on a patient with GH-secreting pituitary macroadenoma associated with a right frontal meningioma and with two intracavernous asymptomatic aneurisms. A 61-year-old woman was referred to our Endocrine Unit 13 years after a right frontal craniotomy for a pituitary tumour. Endocrine investigation showed high levels of IGF-1 (560 ng/ml) and increased basal serum GH (56 ng/ml) levels, not suppressed after OGTT. MRI showed persistence of a homogeneously enhancing intra- and suprasellar lesion, compressing the visual pathways, with bilateral intracavernous invasion and simultaneous coexistence of a right intracavernous internal carotid artery (ICA) aneurysm in direct contact with the pituitary tumour. Somatostatin analog treatment normalized GH and IGF-1 levels. Eight months later, the patient underwent a balloon ICA occlusion with disappearance of the right ICA aneurysm. One year later, a new MRI confirmed the presence of the pituitary mass showing also a right intracranial frontal meningioma and a new ICA aneurysm on the left side. Previous studies have suggested that prolonged GH hypersecretion could play a role in the genesis of intracranial aneurysms, inducing atherosclerotic and/or degenerative modification of the arterial walls. Other aetiological factors include a mechanical effect due to a direct contact between adenoma and aneurysm. Coexistence of pituitary adenoma and intracranial meningioma is a rare event, but also for this association it has been suggested that GH or other growth factors could play a role in appearance or in growth of meningioma. In our case, meningioma appeared and grew, despite the effective treatment of acromegaly.
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PMID:MRI finding of simultaneous coexistence of growth hormone-secreting pituitary adenoma with intracranial meningioma and carotid artery aneurysms: report of a case. 1733 27

Ectopic acromegaly represents less than 1% of the reported cases of acromegaly. Although clinical improvement is common after treatment with somatostatin (SMS) analogs, the biochemical response and tumor size of the growth hormone-releasing hormone (GHRH)-producing tumor and its metastases are less predictable. Subject A 36-year-old male was referred because of a 3-year history of acromegaly related symptoms. He had undergone lung surgery in 1987 for a "benign" carcinoid tumor. Endocrine evaluation confirmed acromegaly Plasma IGF-1: 984 ng/ml (63-380), GH: 49.8 ng/ml (<5). MRI showed a large mass in the left cerebellopontine angle and diffuse pituitary hyperplasia. Pulmonary, liver and bone metastases were shown by chest and abdominal CT scans. Ectopic GHRH secretion was suspected. Methods Measurement of circulating GHRH levels by fluorescence immunoassay levels and immunohistochemical study of the primary lung tumor and metastatic tissue with anti-GHRH and anti-somatostatin receptor type 2 (sst2A) antibodies. Results Basal plasma GHRH: 4654 pg/ml (<100). Pathological study of liver and bone biopsy material and lung tissue removed 19 years earlier was consistent with an atypical carcinoid producing GHRH and exhibiting sst2A receptor expression. Treatment with octreotide LAR 20-40 mg q. month resulted in normalization of plasma IGF-1 levels. Circulating GHRH levels decreased dramatically. The size of the left prepontine cistern mass, with SMS receptors shown by a radiolabeled pentetreotide scan, decreased by 80% after 18 months of therapy. Total regression of pituitary enlargement was also observed. No changes were observed in lung and liver metastases. After 24 months of therapy the patient is asymptomatic and living a full and active life.
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PMID:Ectopic growth hormone-releasing hormone secretion by a metastatic bronchial carcinoid tumor: a case with a non hypophysial intracranial tumor that shrank during long acting octreotide treatment. 1737 89

Herein we report a rare case of a pituitary metastasis from a neuroendocrine tumour mimicking an adenoma. Moreover, starting from this unusual case, the relevant literature concerning the diagnosis and management of patients with metastasis at pituitary level is reviewed. A 69-year-old woman was admitted to our Unit for severe headache, diplopia, and critical visual field impairment. MRI showed a large pituitary mass compressing the optic chiasm and infiltrating the cavernous sinus. Trans-sphenoidal biopsy revealed a pituitary metastasis from a neuroendocrine tumour, in line with the multiple liver lesions that were already considered metastases from an ileal primary neuroendocrine tumour. In vitro receptor characterisation of both pituitary and liver tissues by immunohistochemistry showed a heterogeneous somatostatin receptor subtype pattern, with a predominant expression of sst(2) within the pituitary lesion. However, the liver metastasis receptor profile was completely different from the pituitary. Octreotide LAR was administered first, followed by receptor radiometabolic therapy with radiolabelled somatostatin analogues ((90)Y-DOTATOC and (177)Lu-DOTATATE). After 16 months, MRI showed a significant shrinkage of the sellar mass. Moreover, disappearance of diplopia and visual defects, together with a considerable improvement in quality of life were gradually recorded. To our knowledge, this is the first case of combined treatment using "cold" and radiolabelled octreotide in a pituitary metastasis from a neuroendocrine tumour.
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PMID:Treatment of a pituitary metastasis from a neuroendocrine tumour: case report and literature review. 1745 1

In diffuse brainstem gliomas often surgical biopsies cannot be obtained. The diagnosis relies upon imaging criteria, first line being MRI. Gliomas generally express somatostatin receptors (SSTR), which might enable receptor imaging. We present the case of a female adolescent with acute onset of hallucinations, dysphagia and diplopia. MRI detected a suggestive large pontine glioma. This lesion presented with marked In-111-pentreotide tracer uptake. SSTR-scan provided information about SSTR-expression, tumour viability and extension. Radiopeptide therapy for selected patients might be discussed.
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PMID:Somatostatin-receptor positive brain stem glioma visualized by octreoscan. 1762 56

Early detection of breast cancer is a prerequisite for treatment success and improvement of survival. In tumors under 10mm diameter the standard morphological methods of imaging such as sonography, mammography and MRI imaging are of lesser specificity and loose sensitivity. Under 5mm detection of breast cancer remains a chalenge. Since recent years scinti-mammography using perfusion weighted enrichment of 99m-Tc-MIBI for imaging has become a standard technique indetection of breast cancer. It is superior when ever small lesions with increased perfusion are to be expected. it is used specially in dense breast patients. Other functional methods such as F-18-FDG-PET, C-11-Methionine-PET and the use of Ga-68-Somatostatin- or Ga-68-Bombesin-PET have been discussed for the early detection and therapy control of breast cancer patents. Especially the high specific low background receptor-PET imaging exels over the standard methods because of its ability to detect lesions even below 2 mm, as it has been shown for the Ga-68-DOTA-somatostatins. Because simple exchange of the diagnostic PET isotope against a therapeutical isotope like Lu-177, Y-90, Ga-67 or Cu-67 the receptor PET is directly linked to radio-peptide therapy. As the studies of J. C. Reubi et alii have been shown several peptide receptors are expressed in breast cancer, like the sms receptors and the gastrin releasing peptide receptors (bombesin receptors). One of the most widely expressed receptors expressed in breast cancer, which tends to be relatively selective, is NPY1 receptor. Intensive work had been done on the development of peptide ligands by A. Beck-Sicklinger and her group. These new developed peptides are very promising in combination with somatostatin and bombesin derivatives. Dedicated breast pet devices in combination with these high specific tracers have great potential to open and entire new quality in early detection of breast cancer and may lead to its radiopeptide therapy.
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PMID:From scinti-mammography and metabolic imaging to receptor targeted PET-new principles of breast cancer detection. 1764 85

Malignant solid tumors and leukemias are the second most common causes of death in childhood. The most frequent pediatric solid tumors are brain tumors. Brain tumors, especially medulloblastoma should be treated by surgery, irradiation and chemotherapy. However, chemotherapy has only moderate effect. Pediatric brain tumors, especially medulloblastomas, express somatostatin receptors. The aim of this study was the investigation of the expression of somatostatin receptors in pediatric brain tumors for diagnostic and therapeutic purpose. Fifty-six scintigraphic imagings (111In-DTPA-D-Phe1-octreotide) made in 45 children treated with brain tumor at the Unit of Oncology of the 2nd Department of Pediatrics, Semmelweis University. The diagnosis was medulloblastoma in 21 cases (46.7%). MRI scans have been performed parallel with the Octreoscan images. Octreoscan images were positive in 27 of 56 (48.2%) cases. The 27 positive Octreoscan images consisted of 16 medulloblastomas, 4 ependymomas, 4 astrocytomas and 3 glioblastomas. In 37 (66.1%) cases the results of Octreoscans were the same as those of the MRI scans. However, in 19 scans (33.9%) the outcome was different. Octreoscan imaging is not suitable for differential diagnosis in pediatric brain tumors, including medulloblastomas. Isotopes specifically binding to the somatostatin receptors (111In-DTPA-D-Phe1-octreotide) can be applied in medulloblastomas for diagnosis and follow-up treatment. In Octreoscan-positive tumors the Octreoscan images establish the opportunity to somatostatin analogue and/or specifically targeted radiation therapies.
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PMID:[Imaging of pediatric brain tumors using somatostatin analogue 111Ih-DTPA-D-Phe1-octreotide]. 1792 63

Cross sectional imaging in the assessment of gastrinomas has three major applications: Tumor localization (sporadic gastrinoma, MEN I) in patients undergoing primary or secondary surgery. Staging of metastasized tumors, especially assessment of lymph nodes and liver metastases, possibly including a risk analysis prior to liver resection. Post-surgery follow-up and monitoring of bio- or chemotherapy. Detection of primary tumors is strongly correlated with their size. However, the sensitivity of surgical assessment of the mostly small tumors by experienced surgeons is much higher than that of any imaging modality. Of all imaging modalities, endoultrasonography (EUS) followed by Somatostatin receptor scintigraphy (SRS) is the most sensitive modality for the assessment of pancreatic tumors in asymptomatic patients suffering from a MEN-I syndrome. Scintigraphy has the highest sensitivity in tumors of symptomatic patients and in the assessment of metastases. CT and MRI are only second line diagnostic modalities. Their sensitivity is largely dependent on the selection of patients. As a potential application, 3D reconstruction of nearly isotropic CT data sets for the risk assessment prior to liver resection is currently developing. Due to the absent radiation exposure, MRI is increasingly utilized to monitor the response of metastases under systemic therapy, e.g. in clinical trials.
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PMID:Localisation and staging of gastrin producing tumours using cross-sectional imaging modalities. 1798 93

Pancreatic neuroendocrine tumours are rare tumours ( approximately 1/100,00 population/year) of which 60% are non-functioning. Except for insulinoma all types are malignant in >50% of cases. In multiple endocrine neoplasia (MEN)1, pancreatic neuroendocrine tumours occur in 40-80% of patients and are mostly non-functioning tumours or gastrinomas. Insulinomas are benign in approximately 90%, solitary in 95% of sporadic cases whilst multiple in 90% of MEN1 patients. In contrast approximately 50% gastrinomas and the majority of non-functioning pancreatic neuroendocrine tumours are malignant. Pancreatic neuroendocrine tumours occur in 10-15% of patients with Von Hippel-Lindau (VHL) and are frequently multiple (>30%). Surgical excision is a key aspect of treatment for all cases of sporadic gastrinoma and if >2.5 cm in MEN1. Insulinomas are enucleated if solitary and may require pancreatectomy if multiple. Non-functioning tumours should also be resected if sporadic and if >2 cm in MEN1 or if >2-3 cm in VHL. Tumours <1cm require yearly follow-up by CT or MRI from an early age in VHL. The local treatment for liver metastases is now well established and options include liver resection, chemoembolisation and radiofrequency ablation. Systemic therapies have also been better defined and include radionuclide therapy against somatostatin receptors or MIBG and chemotherapy especially for poorly differentiated tumours. A number of novel agents are currently in clinical development.
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PMID:Pancreatic neuroendocrine tumours. 1820 21

Tumours of the thymus are uncommon and are generally regarded as being indolent. Whilst this is often true of thymomas; thymic adenocarcinoma and thymic neuroendocrine cancer can be aggressive and have a poor prognosis. Understanding the biology of these tumours is important for prognosis and management. The pathological features of these tumours are examined in detail. Imaging modalities for aiding in diagnosis and staging of these tumours are described; this includes CT and MRI, plus more recent advances including the use of FDG-PET and Indium-111 Octreotide scintigraphy. The treatment options available including curative surgery, debulking surgery, chemotherapy, somatostatin analogues and peptide receptor radionuclide therapy are discussed. The optimal chemotherapy regimens are still unclear, although promising results have been obtained with platinum-based chemotherapy. The role for adjuvant therapy in both thymic carcinoma and thymoma is unclear except, in patients with stage I thymomas. There is a high expression of somatostatin receptors in thymic tumours and anti-tumour benefit has been reported in patients treated with somatostatin analogues. A new development is the role of peptide receptor radionuclide therapy. This has become an established therapy in management of gastroenteropancreatic neuroendocrine tumours and its use has been recently described in case reports in both thymoma and thymic carcinoma.
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PMID:A review of thymic tumours. 1834 28


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