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

Endocrine cells of the GI tract derive from stem cells of the neurocrest. They belong to the diffuse endocrine system as defined by Feyrter and share common features, such as the capacity for APUD cells. From these regulatory peptide-producing cells, endocrine tumors may develop with specific clinical symptoms. In some other endocrine GI tumors, no hormone secretion has yet been found, and for some regulatory peptides, no specific clinical entity has yet been identified. Diagnosis can be confirmed by hormone measurements and by specific immunohistochemistry or electron microscopy of the tumor tissue. Metastases synthesize and secrete peptide hormones like those of the primary tumors. The principal target organ for metastases is the liver. Several approaches to treatment of hepatic tumor deposits may reduce tumor mass with consequent reduction of effective plasma hormone levels. There are also systemic treatments for neuroendocrine tumors from the GEP system.
 ...
PMID:Approach to hepatic involvement by endocrine tumors of the gastrointestinal tract. 290 61

High numbers of high-affinity somatostatin binding sites have been found on carcinoid tumors, gastrinomas, small cell lung cancers and the majority of medullary thyroid cancers, enabling in vivo visualization of these tumors with octreotide scintigraphy. A comparison of the results obtained at our institution and another 15 centers in Europe show a few remarkable similarities and differences. The overall sensitivity of octreotide receptor scintigraphy to detect the primary GEP tumor and its metastases is high, e.g. 80-90%. The main difference was found in gastrinomas and to a lesser extent in insulinomas. These differences might be attributed to different scanning protocols. Furthermore, octreotide scintigraphy also has a high sensitivity to localize the primary tumor and its metastases causing Cushing's syndrome by ectopic production of ACTH or CRH. Octreotide scintigraphy is a new, sensitive and noninvasive technique to localize somatostatin receptor expressing endocrine tumors and their metastases.
 ...
PMID:Somatostatin receptor scintigraphy in carcinoids, gastrinomas and Cushing's syndrome. 769 38

Receptor scintigraphy with 111In-pentetreotide is a complementary imaging technique with a sensitivity of 88% for the localization of the primary tumor and its metastases in patients presenting with the clinical and biochemical symptoms of an endocrine tumor of the gastrointestinal tract or the pancreas. As a whole-body scintigraphic technique it covers all body regions and is also able to reveal small tumors which can only be detected with difficulty or not at all by the usual imaging methods. In 104 patients with GEP tumors or after operative removal of such tumors, receptor scintigraphy proved to be superior to ultrasound and computed tomography in 34%, equal in 52% and inferior in 14% of the cases.
 ...
PMID:[Receptor scintigraphy using 111In-pentetreotide in endocrine gastroenteropancreatic tumors]. 790

Receptor scintigraphy with 111In-pentetreotide is a simple method with a sensitivity of 86% for the localization of the primary tumor and its metastases in patients presenting with the clinical and biochemical symptoms of an endocrine tumor of the gastrointestinal tract or the pancreas. As a whole-body scintigraphic technique it covers all body regions and is also able to reveal small tumors which either cannot be detected or can only be detected with difficulty by the usual imaging methods. In 85 patients with GEP tumors or after operative removal of such tumors, receptor scintigraphy proved to be superior to ultrasound and computed tomography in 34%, equal in 52%, and inferior in 14% of the cases.
 ...
PMID:Receptor scintigraphy with 111In-pentetreotide for endocrine gastroenteropancreatic tumors. 833 Aug 69

Previous studies of the intraoperative use of a hand-held gamma probe to localize metastases and primary tumors of colorectal cancer have shown improved assessment of tumor spread and changes in surgical management based on added information gained by radioimmunoguided surgery. Following the injection of 180 MBq [111In-DTPA-D-Phe1]-pentetreotide and/or 500 MBq 99mTc-dimercaptosuccinic acid (both for dual-radionuclide scintigraphy) preoperative somatostatin receptor imaging [11 patients with GEP tumors] and dual-radionuclide scintigraphy. (8 patients with relapsing medullary thyroid carcinomas) was performed. One patient with a metastasizing pheochromocytoma underwent 123]-MIBg scintigraphy. Results were combined with the information obtained from conventional imaging modalities. Intraoperative radiodetection was performed 24 hours after administration of [111In-DTPA-D-Phe1]-pentetreotide or 4 hours following the injection of 99mTc(V)DMSA using a hand-held gamma probe (Tec Probe 2000. Stratec, FRG). Intraoperative gamma counting localized 39 somatostatin receptor positive lesions of GEP tumors whereas preoperative receptor imaging visualized 81%, surgical palpation 41% and radiological imaging modalities localized only 31%. In 8 patients with recurrent medullary thyroid carcinoma the surgeon was successful in localizing and removing 18 tumor lesions by the help of the gamma probe. Dual-radionuclide scintigraphy revealed 77% (Octreoscan 5/18; 99mTc-V-DMSA 9/18), surgical palpation 55% and conventional imaging methods (CT, sonography) only 38% of all lesions detected intraoperatively by the hand-held gamma probe. In summary, this preliminary data show that intraoperative hand-held gamma probe detection of microscopic and occult endocrine tumors is feasible and more sensitive than external scintigraphy and conventional imaging.
 ...
PMID:[Pre- and intraoperative localization of neuroendocrine tumors]. 927 12

Scintigraphy using [111In-DTPA-d-Phe1]-pentetreotide or pentavalent technetium-99m-dimercaptosuccinic acid [99mTc(V)-DMSA] has been shown to localize well-differentiated and slowly growing neuroendocrine tumours, whereas increased fluorodeoxyglucose (FDG) uptake is associated with malignancy. The aim of this study was to compare the value of fluorine-18 FDG positron emission tomography (PET) with that of somatostatin receptor scintigraphy (SS-R) and dual-radionuclide scintigraphy [SS-R and 99mTc(V)-DMSA = DNS] in detecting malignant neuroendocrine tumours. Fifteen patients with metastasizing gastroenteropancreatic tumours (GEP tumours; n = 7), medullary thyroid carcinomas (MTCs; n = 8) and elevated tumour markers [GEP tumours: 5-hydroxyindoleacetic acid, insulin; MTCs: calcitonin, carcinoembryonic antigen (CEA)] were studied. Prior to PET, all patients with GEP tumours underwent SS-R. DNS was performed in all patients with MTC. Patients had been fasting for at least 12 h and normal glucose plasma levels were confirmed. Sixty minutes after intravenous administration of 18F-FDG (mean: 374 MBq) whole-body PET and regional scans were performed. In addition, the resected tissues were prepared for immunocytochemistry examination (cell cycle-associated Ki-67 antigen). In two patients with less-differentiated GEP tumours associated with high proliferative activity and increased FDG uptake, SS-R failed to detect any lesion. In comparison, in four patients with well-differentiated GEP tumours showing low proliferative activity, SS-R localized four primary tumours, 22 lymph node metastases and 18 malignant liver lesions, whereas 18F-FDG PET demonstrated normal distribution. In one patient with a metastasizing carcinoid (medium proliferative activity) SS-R localized multiple metastases, whereas PET demonstrated low FDG uptake in all known metastases. In patients with recurrent MTC and rapidly increasing CEA levels DNS detected only three lesions in two patients, whereas PET demonstrated one pulmonary, three osseous, 20 mediastinal, ten locoregional, and four liver metastases in seven patients. Twenty-nine malignant lesions were confirmed by follow-up and nine lymph node metastases could be surgically removed. In conclusion, PET imaging of gastroenteropancreatic tumours revealed increased glucose metabolism only in less-differentiated GEP tumours with high proliferative activity and metastasizing MTC associated with rapidly increasing CEA levels. Therefore, additional 18F-FDG PET should be performed only if SS-R or DNS is negative.
 ...
PMID:Limited value of fluorine-18 fluorodeoxyglucose positron emission tomography for the imaging of neuroendocrine tumours. 939 78

A general characteristic of GEP endocrine tumours is that vast majority produce and secrete a multitude of peptide hormones and amines. The rarity of these types of tumours, their possible episodic expression and the variable clinical symptoms, are the reasons why patients are often diagnosed late in the advanced stages of the disease. For these reasons, the patients with advanced metastatic disease should be treated aggressively with medical and surgical therapies aimed at reducing both symptoms and complications through strategies that reduce tumour bulk and block hormonal effects. The medical treatment of functioning endocrine tumours of the gastrointestinal tract must be based on the growth properties of the tumour and includes chemotherapy, somatostatin analogs, alpha-interferon alone and associated with somatostatin analogs, chemoembolization and radiolabelled somatostatin analogs. Even if chemotherapy has been basis of therapy for these types of tumours for a long time, it is currently reserved for progressive disease and anaplastic tumours. Biotherapy, with interferon and somatostatin analogs has been demonstrated to have a significant antitumor effect and causes an improvement of symptoms in patients with functioning neuroendocrine tumours. Furthermore, these drugs produce a notable improvement in the quality of life. Radioactive targeting therapy is the most promising new treatment modality for patients who have SST receptor positive tumours.
 ...
PMID:Basis for treatment of functioning neuroendocrine tumours. 1507 10

Metastasis is a multi-step process involved in the progression of breast cancer to a disease with poor prognosis. Growth factor and/or growth factor receptor over- expression have been reported to play an important role in this process. The 88 kDa glycoprotein PC cell-derived growth factor (PCDGF/GP88), also known as progranulin, has been shown to play a major role in breast tumorigenesis by stimulating proliferation, mediating survival and conferring resistance to tamoxifen. In the present paper, the metastatic potential of PCDGF/GP88 was examined in breast cancer. Using MCF-7 cells, we showed that PCDGF/GP88 over-expression stimulated anchorage-independent cell growth and accelerated cell migration through matrigel. Similar results were obtained with MCF-7 cells treated exogenously with PCDGF/GP88. Furthermore, gelatin zymograph and immunoblot revealed that matrix metalloprotease-9 was up-regulated by PCDGF/GP88. PCDGF/GP88 stimulated VEGF expression in MCF-7 cells. These results suggest that PCDGF/GP88 could act to promote metastasis and angiogenesis in human breast cancer cells in addition to stimulating their proliferation and survival.
 ...
PMID:PC cell-derived growth factor (PCDGF/GP88, progranulin) stimulates migration, invasiveness and VEGF expression in breast cancer cells. 1511 9

Somatostatin receptors are expressed in selected human cancers. They are particularly frequently expressed in gastroenteropancreatic neuroendocrine tumors (GEP NET), including both primaries and metastases. The density is often high, the distribution is usually homogeneous. While various somatostatin receptor subtypes can be expressed in these tumors, sst2 is clearly predominant. These receptors represent the molecular basis for a number of clinical applications, including symptomatic therapy with cold octreotide in hormone-secreting GEP NET, in vivo diagnostic with Octreoscan to evaluate the extend of the disease, and 90Y-DOTATOC radiotherapy. GEP NET can, however, express peptide receptors other than somatostatin receptors: insulinomas have more glucagon-like peptide 1 receptors than somatostatin receptors, gut NET (carcinoids) may also express cholecystokinin 2, bombesin or vasoactive intestinal peptide receptors. Often, several of these peptide receptors are expressed simultaneously in GEP NET, providing a molecular basis for in vivo multireceptor targeting of those tumors.
 ...
PMID:Somatostatin and other Peptide receptors as tools for tumor diagnosis and treatment. 1547 18

Carcinoid tumours are rare neuroendocrine tumours. In 2000 the WHO developed a new classification which gives a better description of the characteristics and biological behaviour of the tumour. Their advised designation is gastroenteropancreatic neuroendocrine tumour (GEP-NET). Somatostatin receptor scintigraphy has the highest sensitivity for visualisation of GEP-NETs. In the recent past years new positron emission tomography (PET) tracers have been developed and PET scanning is likely to become an important tool in the near future. Surgical resection is the treatment of first choice for a patient with a GEP-NET. In metastatic disease a number of forms ofpalliative treatment are possible. Cytotoxic chemotherapy seems only to be effective in aggressive, poorly-differentiated tumours. Therapy with somatostatin analogues leads to objective tumour regression in a minority of patients only. New advances in peptide receptor radionuclide therapy using radioactive-labelled somatostatin analoga are showing better results.
 ...
PMID:[Gastroenteropancreatic neuroendocrine tumours (carcinoid tumours): definition, clinical aspects, diagnosis and therapy]. 1710 97


1 2 3 4 5 6 7 8 Next >>