Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Radiolabeled somatostatin analogs are potentially of considerable value in both the localization and treatment of somatostatin receptor-bearing tumors. Whole body 123I-labeled Tyr3-octreotide scintigraphy is capable of detecting and localizing primary tumors and metastatic disease that may not be detectable by other methods. Although it is possible that this technique may be applicable to a wide variety of neoplasms, 123I-Tyr3-octreotide scans appear particularly useful for imaging various gut neuroendocrine tumors, meningiomas, and paragangliomas. This primarily reflects the level of expression of somatostatin receptors by these lesions. In addition to whole body scintigraphy, intraoperative localization by receptor identification utilizing a hand-held gamma detector probe may prove to be an effective means of identifying spread and micrometastasis of somatostatin receptor-bearing tumors. Aside from identification and topographic localization of disease, the detection of an 123I-Tyr3-octreotide labeled tumor may be utilized as in vivo assay for the presence of somatostatin receptors. Such observations may prove useful in predicting the susceptibility of an individual tumor to octreotide therapy. Additionally, it may prove possible to deliver a therapeutic dose of radiation to receptor-bearing tumors by the administration of specific radiolabeled somatostatin analogs.
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PMID:Use of radiolabeled somatostatin analogs in the identification and treatment of somatostatin receptor-bearing tumors. 835 74

In this review, we evaluate radiological techniques currently used to localize gastroenteropancreatic (GEP) endocrine tumors. We also describe the visualization, using intravenous administration of two isotope-labelled somatostatin analogs (123-I-Tyr3-octreotide and 111In-DTPA-octreotide), of islet cell tumors in 25 patients and carcinoids in 39 patients. The primary tumor as well as previously unrecognized distant metastases were visualized in 20 of the 25 patients (80%) and in 37 of the 39 (95%). Parallel in vitro detection of somatostatin receptors on those tumors also visualized in vivo showed that ligand binding to the tumor in vivo represents binding to specific somatostatin receptors. The detection of somatostatin receptors on tumors in vivo predicted a good suppressive effect of octreotide on hormonal hypersecretion by these tumors. It is an easy, quick and harmless procedure, valuable in the localization of primary endocrine pancreatic tumors and their often radiologically and clinically unrecognized metastases. Future prospective controlled studies comparing this procedure with other radiological investigative techniques should demonstrate its sensitivity and specificity and determine the place of somatostatin receptor imaging in the localization of GEP endocrine tumors.
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PMID:The visualization of gastroenteropancreatic endocrine tumors. 839 33

Various tumours, classically specified as either neuroendocrine or non-neuroendocrine, contain high numbers of somatostatin receptors, which enable in vivo localization of the primary tumour and its metastases by scintigraphy with the radiolabelled somatostatin analogue octreotide. In addition granulomas and autoimmune processes can be visualized because of local accumulation of somatostatin receptor-positive activated mononuclear leucocytes. In many instances a positive scintigram predicts a favourable response to treatment with octreotide. It is tempting to speculate that octreotide labelled with an appropriate radionuclide might be used in cancer therapy. The successful application of radiolabelled octreotide in scintigraphy indicates the possible usefulness of other radiolabelled peptides, either native peptides or derivatives of these, in, for example, nuclear oncology. The small size of these peptides, e.g. bombesin and substance P, is of the utmost importance for a relatively fast blood clearance, thus leading to low background radioactivity. In this way peptides are powerful alternatives to (fragments of) monoclonal antibodies, the application of which to scintigraphic localization of specific cell surface antigen-bearing tumours is plagued by slow blood clearance and, hence, high background levels.
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PMID:Somatostatin receptor scintigraphy with [111In-DTPA-D-Phe1]- and [123I-Tyr3]-octreotide: the Rotterdam experience with more than 1000 patients. 840 61

Scintigraphy with a radiolabelled somatostatin analog represents a new highly specific approach in the diagnostic work-up of receptor-positive APUD tumours and their metastases. We present our preliminary results with somatostatin receptor scintigraphy in 15 patients with histologically proven midgut carcinoid. 5 out of 6 primary tumour sites (83%) and 90% of the known metastatic lesions could be detected; unknown metastatic lesions were seen in 5 patients. Compared with other nuclear medicine procedures somatostatin receptor scintigraphy is able to detect all tumour sites within hours. This advantage will promote the acceptance of this sensitive and specific imaging modality by the clinicians with regard to preoperative work-up and symptomatic therapy with a somatostatin analog.
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PMID:[Somatostatin receptor scintigraphy. A new imaging procedure for the specific demonstration of carcinoids of the small intestine]. 842 79

Five somatostatin receptor subtypes (sst1 to sst5) have been cloned. We demonstrated previously that sst2 and sst5 mediate the antiproliferative effect of the somatostatin analogues octreotide and vapreotide. Using reverse transcription-PCR, we investigated gene expression of the five receptors in 47 human normal and cancerous tissues or cell lines from pancreatic and colorectal origin. mRNAs of somatostatin receptor subtypes were detected in 98% of samples, with more than two mRNA subtypes being expressed in 55% of cases. sst1, sst4, and sst5 were heterogeneously expressed in both normal and cancerous tissues; sst3 was rarely or not expressed. sst2 was present in normal pancreatic tissues but was absent in exocrine pancreatic carcinomas and their metastases. sst2 mRNAs were detected in normal colon, sporadic polyadenomas, and 50% of Dukes' stage B and 20% of Dukes' stage C carcinomas but were undetectable in Dukes' stage D carcinomas, hepatic metastases, and adenomas from familial adenomatous polyposis. The loss of sst2 expression could represent a growth advantage in these tumors and provide an explanation for the lack of therapeutic effect of somatostatin analogues in such adenocarcinomas. A subtyping of somatostatin receptors should be carried out before considering a somatostatin analogue treatment in patients with colorectal or pancreatic cancer.
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PMID:Loss of sst2 somatostatin receptor gene expression in human pancreatic and colorectal cancer. 862 Apr 99

Most carcinoid primary tumors are small and do not cause symptoms until complications (e.g. intestinal obstruction) or symptoms and signs of the carcinoid syndrome occur. Therefore in most cases an assessment of the primary tumor and its metastases must be performed. To determine the value of somatostatin receptor scintigraphy (SRS) for localizing carcinoid tumors, we compared the results of SRS with those obtained with computed tomography (CT) and ultrasonography (US) in 22 patients who had not undergone surgery for removal of the primary tumor. We could not find an advantage of SRS over CT and US for detecting the primary lesions. Tumors > 2 cm in diameter were regularly detected using all methods. SRS was not superior to CT or US for the detection of liver metastases. SRS showed the liver metastases in 16 of 18 patients, whereas CT and US detected liver metastases in all patients. For localization of extrahepatic abdominal and extraabdominal metastases (lymph nodes, bone), whole-body SRS showed an advantage over CT and US. We conclude that SRS is not superior to CT or US for localization of primary carcinoid tumors or liver metastases, although it did prove successful for visualizing extrahepatic and extraabdominal tumor spread. Additionally, SRS is useful for identifying receptor-positive metastases that may be treated by somatostatin analogs. Thus SRS should be performed in patients with a known carcinoid tumor, except those with an appendiceal carcinoid measuring < 1 cm in diameter.
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PMID:Value of somatostatin receptor scintigraphy for preoperative localization of carcinoids. 866 12

We report a case of left ventricular (LV) myocardial uptake of a labeled somatostatin analog in a patient with a carcinoid tumor of the small bowel. The patient developed liver metastases and a carcinoid syndrome, including right carcinoid heart disease, without right-to-left shunt on contrast ultrasonography or left ventricular myocardial metastases. The basis for visualization of the LV myocardium is probable somatostatin receptor upregulation.
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PMID:Left ventricular myocardial uptake of a labeled somatostatin analog in carcinoid syndrome. 866 61

An observed case of carcinoid tumor of the large-bowel in a 68-year-old woman leads to an analysis of the clinical-diagnostic and therapeutic aspects of this rare gastrointestinal tumour. Carcinoid tumour represents 0.8-1.5% of malignant digestive tumours, in 6% of cases it is localized in large-bowel and in 2-3% in cecal-bowel. In our experience there is no specific symptoms and diagnosis was based on postoperative histopathologic analysis. Right hemicolectomy with lymphadenectomy performed and the operative specimen included a 7 cm diameter tumour, which had narrowed the lumen by 80% and infiltrated ileocecal valve. Carcinoid tumour presents considerable problems of diagnosis because symptoms are aspecific. Diagnosis is possible only in patients with high urinary levels of 5-HIAA, in presence of carcinoid syndrome and by endoscopic biopsy when tumour infiltrated gastrointestinal mucosa. False negative cases are frequent in small carcinoids ( < 2 cm) because the tumour tissues are covered by integral mucosa. C.T., ultrasonography and angiography play a primary role in the diagnosis of this tumour but octreotide scintigraphy is very important for tumour and metastases localization in consequence of its ability to demonstrate somatostatin receptor positive tumours. Radical surgery is the only treatment in very little carcinoids to prevent metastases risk. Determinant risk factors are: primary size, localization, serosal penetration. In patients with any of these risk factors, resection with regional lymphadenectomy is recommended. Other prognostic factors include histologic differentiation, the presence of macroscopic residual disease after initial surgery and level of 5-HIAA in urine. We think that neither adjuvant chemotherapy, or radiotherapy may play a significant role in this neoplasm. Many authors report considerable unsuccessful with this treatment and it is used mainly for palliation. At present, the medical treatment of inoperable gastrointestinal carcinoid consist in association with interferon alpha and octreotide. During this treatment the size of the tumour is stable: reduction of symptoms and 5-HIAA urinary levels are noted.
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PMID:[A carcinoid with cecal localization. Apropos a case]. 867 47

The aim of this study was to evaluate somatostatin receptor scintigraphy (SRS) in the staging of patients with small cell lung cancer. Prior to chemotherapy, 20 patients were investigated up to 24 h following an injection of 200 MBq 111In-octreotide. Following chemotherapy and restaging, four patients were re-evaluated. Primary tumour was detected in 18 of 23 studies, which exhibited increasing target-to-back-ground ratios over time. Lymph node metastases and distant metastases were detected in 7 of 27 and 8 of 31 sites, respectively. Thus, the overall sensitivity for detecting metastases was less than 26%. SRS did not result in any upstaging of patients. We conclude that in patients with small cell lung cancer, functional imaging by SRS has no impact on clinical decision making.
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PMID:Somatostatin receptor scintigraphy in the staging of small cell lung cancer. 869 84

Through the development of somatostatin scintigraphy with the labeled somatostatin analog Indium111-Octreotide, it has recently become possible to accurately diagnose primary tumors of the APUD system as well as their metastases, since these tumors usually have somatostatin receptors. Experience with this method is already available for endocrine and exocrine tumors of the gastrointestinal tract, neuroendocrine and breast tumors, small cell bronchial carcinomas and certain lymphomas. In the present study, this new diagnostic technique was used for the first time in various head and neck tumors (carcinoid of the larynx, Merkel cell tumor, glomus tumor of the carotid and glomus jugulare tumor). Concurrently, some of these tumors shown by this diagnostic method to be somatostatin receptor positive were treated using the somatostatin analog Octreotide, a therapeutic approach new for the ENT-specialty. Our initial results prove that the detection of the ENT tumors which we studied by means of receptor scintigraphy is reliable. The preliminary results of this Octreotide therapy show a growth inhibitory effect, especially for those tumors of the head and neck which are inoperable or are difficult to approach surgically.
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PMID:Somatostatin receptor scintigraphy and therapy of neuroendocrine (APUD) tumors of the head and neck. 872 46


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