Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 77 percent of patients suffering from a malignant carcinoid syndrome, administration of the somatostatin analog, octreotide (SMS 201-995, Sandostatin) induced clinical improvement coupled with a decrease in 24-hour urinary 5-hydroxyindole acetic acid (5-HIAA). This finding prompted an evaluation to determine the correlation between the presence of somatostatin receptors in tumor tissue and the response to octreotide in patients with advanced, metastatic, neuroendocrine tumors. In tissues of 31 tumors (20 carcinoid, eight islet-cell carcinoma, three medullary thyroid carcinomas), the presence of somatostatin receptors was analyzed by binding of the somatostatin analog 125I-Tyr3-SMS 201-995 and autoradiography. Receptors were detected in 16 of 20 samples of carcinoid tissues; all but one patient with receptor-positive tumors improved clinically after treatment with octreotide, and the urine 5-HIAA level was reduced a median of 63 percent (range, 39-94 percent) compared to values before treatment. Of the receptor-negative carcinoid patients, only one showed clinical improvement, which was minimal, and there was a negligible reduction in 5-HIAA after octreotide therapy. All eight patients with metastatic islet-cell carcinomas were positive for somatostatin receptors. Symptomatic improvement and a > 50 percent decrease in the level of at least one of the pathologically elevated marker hormones was seen in all eight. None of the three patients with medullary carcinoma of the thyroid had a decrease in calcitonin, and all three were initially somatostatin receptor-negative. We conclude that the presence of somatostatin receptors in malignant neuroendocrine tumor tissue appears to correlate with the response to octreotide therapy. Analysis of somatostatin receptors in malignant neuroendocrine carcinoma tissue should be included in future prospective clinical trials of this synthetic peptide.
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PMID:The presence of somatostatin receptors in malignant neuroendocrine tumor tissue predicts responsiveness to octreotide. 136 90

A number of neoplasms are known to express somatostatin receptors, and the use of somatostatin receptor imaging in their localization has recently been described. We compared an 123I-labeled somatostatin analog Tyr-3-octreotide (TOCT) and 123I-labeled metaiodobenzylguanidine (MIBG) scintigraphy in seven patients with histologically proven metastatic carcinoid tumors. The optimum time for identifying tumor uptake on scanning after [123I]MIBG was 24-48 hr, and after 123I-TOCT 10-30 min postinjection. Both radiopharmaceuticals showed a varying spectrum of tracer uptake ([123I]MIBG showed no uptake in one patient; minimal in two; moderate in two; and intense in two; 123I-TOCT showed no uptake in two patients; minimal uptake in one; moderate uptake in two; and intense uptake in two). In two patients, 123I-TOCT identified metastatic lesions not seen by [123I]MIBG scintigraphy. These preliminary results suggest that [123I]MIBG and 123I-TOCT are useful and complementary imaging techniques for detecting metastatic carcinoid tumors.
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PMID:A scintigraphic comparison of iodine-123-metaiodobenzylguanidine and an iodine-labeled somatostatin analog (Tyr-3-octreotide) in metastatic carcinoid tumors. 159 26

Because of its widespread distribution within the nervous system and the gastro-enteropancreatic (GEP) system and its diverse physiological inhibitory actions on various gastrointestinal functions, including endocrine and exocrine secretion, motility, liver and splanchnic blood flow and absorption, native somatostatin has been viewed as a possible therapy for many diseases. However, its short duration of action and consequent limited clinical usefulness have been overcome with the availability of Sandostatin, a long-acting, synthetic octapeptide analogue of the naturally occurring hormone. Sandostatin represents a significant advance in the treatment of GH and TSH secreting pituitary tumours and GEP endocrine tumours (carcinoid tumour, VIPoma, glucagonoma, insulinoma, and gastrinoma). Preclinical in vitro and animal studies have shown the antineoplastic activity of the compound. Moreover, because of a possible direct effect on somatostatin receptor-positive endocrine tumour cells and indirect effect whereby Sandostatin lowers GH, IGF-1 and numerous gastrointestinal peptides, Sandostatin may prove useful as an adjunctive therapy in cancer patients. In vivo labelling of somatostatin receptor-positive tumours with radiolabelled somatostatin analogues now allows localisation of such tumours and their metastases. Moreover, targeted irradiation of these tumours by beta particle emitting isotopes attached to such somatostatin analogues may become possible. The use of Sandostatin in acute oesophageal variceal bleeding, pancreatic pseudocysts, gastrointestinal and pancreatic external fistulae, short bowel syndrome, dumping syndrome and AIDS-related refractory hypersecretory diarrhea has provided encouraging results. Preliminary reports indicate efficacy of Sandostatin in psoriasis, autonomic neuropathy (postprandial and orthostatic hypotension) and its ability to reduce height velocity in tall adolescents. The ultimate role of Sandostatin as a therapeutic agent in these disorders is being explored in prospective clinical trials.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Future medical prospects for Sandostatin. 198 Jul 78

Because of its widespread distribution within the nervous system and gastroenteropancreatic (GEP) system, and its diverse physiological inhibitory actions on various gastrointestinal functions, including endocrine and exocrine secretion, motility, liver and splanchnic blood flow and absorption, native somatostatin has been viewed as a possible therapy for many diseases. However, its short duration of action and consequent limited clinical usefulness have been overcome with the availability of Sandostatin (octreotide, Sandoz Ltd), a long-acting, synthetic octapeptide analog of the naturally occurring hormone. Sandostatin represents a significant advance in the treatment of growth hormone (GH) and thyrotropin (TSH)-secreting pituitary tumors and GEP endocrine tumors (carcinoid tumor, VIPoma, glucagonoma, insulinoma, and gastrinoma). Preclinical in vitro and animal studies have shown the antineoplastic activity of the compound. Moreover, because of a possible direct effect on somatostatin receptor-positive endocrine tumor cells and an indirect effect whereby Sandostatin lowers GH, insulin-like growth factor type 1 (IGF-1), and numerous gastrointestinal peptides, Sandostatin may prove useful as an adjunctive therapy in cancer patients. In vivo labeling of somatostatin receptor-positive tumors with radiolabeled somatostatin analogs now allows localization of such tumors and their metastases. In addition, targeted irradiation of these tumors by beta particle-emitting isotopes attached to such somatostatin analogs may become possible. The use of Sandostatin in acute esophageal variceal bleeding, pancreatic pseudocysts, gastrointestinal, and pancreatic external fistulae, short bowel syndrome, dumping syndrome and acquired immunodeficiency syndrome (AIDS)-related refractory hypersecretory diarrhea has provided encouraging results.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Future medical prospects for Sandostatin. 220 87

We have performed 100 scintigraphic investigations using [111In-diethylenetriaminepentaacetic acid-D-Phe1]octreotide (111In-octreotide) single photon emission tomography (SPECT) in patients with carcinoid tumors. One or several lesions could be detected in 77 cases, and true negative results were obtained in 11 cases. There were false-negative results in 12 cases compared with results from conventional radiological methods. The ratio between the SPECT signals from the area with the highest uptake and normal lung was used as a tumor:background ratio. An attenuation correction was made in all investigations. We found that lesions in untreated patients had lower tumor:background ratios compared with those in patients treated with somatostatin analogues (medians, 10 and 40, respectively; P < 0.001) or IFN (median, 23; P = 0.03). In untreated patients, there was a correlation between the tumor:background ratio and the levels of urinary 5-hydroxyindoleacetic acid (U-5HIAA) and p-chromogranin A. The data obtained in the present investigation indicate that somatostatin receptor expression might be influenced by the treatment; i.e., a higher tumor:background ratio is found in patients treated with either somatostatin analogues or IFN. Furthermore, it was found that somatostatin receptor expression correlates with the levels of U-5HIAA and p-chromogranin A in untreated patients, and that 111In-octreotide SPECT scintigraphy is more likely positive in patients with elevated U-5HIAA values. This indicates that somatostatin receptor expression and elevated U-5HIAA are more likely present in patients with highly differentiated tumors and, thus, could be of prognostic value.
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PMID:Somatostatin receptor scintigraphy in patients with carcinoid tumors: comparison between radioligand uptake and tumor markers. 749 49

Intraoperative radionuclide detection using 111In-DTPA-D-Phe1-octreotide was evaluated in five patients with midgut carcinoids and in three patients with recurrent medullary thyroid carcinoma. Three different time intervals (24, 48 and 120 hr) from injection of the radiopharmaceutical to surgery were used. At surgery, suspect tumors were measured by probe in situ and ex vivo after excision. All tissue specimens and blood samples withdrawn during surgery were measured for 111In activity, and tissue/blood activity concentration ratios were calculated. In situ measurements were valuable especially in neck surgery, where the probe was helpful not only in localization of tumors but also in the control of tumor clearance. Ex vivo measurements were helpful in diagnosing tumor tissue. All five patients with midgut carcinoids were somatostatin receptor-positive, while only three out of seven patients with medullary thyroid carcinoma were receptor-positive. The tissue/blood activity concentration ratios and probe measurement ratios were in general higher in patients with midgut carcinoid than in patients with medullary thyroid carcinoma. Of particular interest were the high tissue/blood concentration ratios in all receptor-positive patients at all time intervals studied. This fact suggests a potential role for radiolabelled octreotide in radiotherapy of these tumor types.
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PMID:Somatostatin receptors on neuroendocrine tumors--a way to intraoperative diagnosis and localization. 750 30

The presence of transcripts for somatostatin receptor (SSTR) subtypes 1, 2, 3, and 4 was probed by reverse transcription and polymerase chain reaction in ribonucleic acid isolated from 46 malignant and 9 nonmalignant breast tissues, 15 carcinoid tumor tissues, and 13 renal cell carcinoma tissues. The transcripts for SSTR2 were amplified in all but 2 tissue samples, whereas transcripts for SSTR1, SSTR3, and SSTR4 were detected sporadically. In renal cell tumors, SSTR3 transcripts were completely absent. In breast cancer tissue, SSTR subtypes were transcribed independently of patient age, menstrual status, diagnosis, histological grade, and levels of estrogen receptor and progesterone receptor. The probability of finding transcripts for SSTR subtypes, P, was ranked differently for the three types of tumor tissues. For breast cancer, P2 > P3 = P1 > P4; for carcinoid tumors, P2 > P1 > P3 = P4; and for renal cell tumors, P2 > P1 > P4 > P3.
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PMID:Expression of somatostatin receptor subtypes in breast carcinoma, carcinoid tumor, and renal cell carcinoma. 755 83

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.
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PMID:Somatostatin receptor scintigraphy in carcinoids, gastrinomas and Cushing's syndrome. 769 38

Somatostatin receptors are expressed on certain neural crest-derived tumors, including pancreatic islet cell and carcinoid tumors, medullary thyroid carcinomas, pheochromocytomas, and paragangliomas. The authors evaluated the expression of high affinity somatostatin receptors in childhood neuroblastoma using autoradiography techniques with the somatostatin analogue 125I-octreotide or 125I-[Leu8,D-Trp22,Tyr25]-SS-28 as the radioligand. Thirty tumors from 30 children with neuroblastoma were analyzed. Twenty-three of 30 tumors that were tested expressed somatostatin receptors. Correlation of somatostatin receptor expression with survival was statistically significant. The survival of those patients whose tumors expressed somatostatin receptors was of longer duration than that of patients whose tumors did not. This was an independent prognostic factor. Somatostatin receptors were expressed more frequently in tumor tissue from patients with lower stages of disease and in those with no evidence of N-myc amplification. Tumoral somatostatin receptors are expressed in a subgroup of patients with childhood neuroblastoma. Survival analysis in this group of patients indicates that somatostatin receptor expression is a favorable prognostic factor. This finding may have important implications for the therapy of children with this malignancy.
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PMID:Expression of somatostatin receptors in childhood neuroblastoma. 780 87

This study was performed to evaluate whether the presence or absence of somatostatin receptors in malignant carcinoid tumours detected by [111In-DTPA-D-Phe1]octreotide scintigraphy can be used to predict response to somatostatin analogue treatment. Thirty patients were investigated, 28 with midgut carcinoid tumours and two with foregut carcinoid tumours. Twenty-seven patients showed pathological uptake in tumour lesions at scintigraphy; of these, 22 responded to somatostatin analogue treatment using octreotide, somatuline or octastatin, while five patients failed to respond. None of the three patients displaying negative scintigraphic investigations responded to treatment with somatostatin analogues. These results show a good correlation between the somatostatin receptor status and the patients' ability to respond to somatostatin analogue treatment (p = 0.014). We conclude that somatostatin receptor scintigraphy using [111In-DTPA-D-Phe1]octreotide can be used to select patients with malignant carcinoid tumours suitable for somatostatin analogue treatment and exclude those that will not benefit from such medication.
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PMID:[111In-DTPA-D-Phe1]octreotide scintigraphy in patients with carcinoid tumours: the predictive value for somatostatin analogue treatment. 780 38


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