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)

Gastrointestinal (GI) stromal tumors (GISTs) are the most common mesenchymal tumors specific to the GI tract, generally defined as KIT (CD117)-positive tumors with a characteristic set of histologic features. These tumors, derived from Cajal cells or their precursors, most commonly occur at the age >50 years in the stomach (60%), jejunum and ileum (30%), duodenum (4-5%), rectum (4%), colon and appendix (1-2%), and esophagus (<1%), and rarely as apparent primary extragastrointestinal tumors in the vicinity of stomach or intestines. Their overall incidence has been estimated as 10 to 20 per million, including incidental minimal tumors. GISTs are rare in children (<1%) and almost exclusively occur in stomach. They are common in patients with neurofibromatosis 1, who have a predisposition to (multiple) small intestinal GISTs. GISTs contain a spectrum from minute indolent tumors to sarcomas at all sites of occurrence. Their gross patterns are diverse, including nodular, cystic, and diverticular tumors. External involvement of pancreas and liver can simulate primary tumor in these organs. In general, gastric tumors have a more favorable prognosis than the intestinal ones with similar parameters. Gastric GISTs < or =10 cm and < or =5 mitoses per 50 HPFs have a low risk for metastasis, whereas those with >5 per 50 HPFs and >5 cm in diameter have a high risk for metastasis. In contrast, all intestinal GISTs >5 cm independent of mitotic rate have at least moderate risk for metastases, and all >5 mitoses per 50 HPFs have a high risk for metastases. Intestinal GISTs < or =5 cm with < or =5 mitoses per 50 HPFs have a low risk for metastases. Gastric GISTs can be divided into histologic subgroups including 4 spindle cell and 4 epithelioid variants. Intestinal GISTs are a histologically more homogeneous group and often contain distinctive extracellular collagen globules, skeinoid fibers. Immunohistochemical demonstration of KIT, CD34, or protein kinase theta positivity helps to properly identify these tumors.
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PMID:Gastrointestinal stromal tumors: pathology and prognosis at different sites. 1719 20

c-KIT is a tyrosine kinase receptor found to be overexpressed in several tumours, namely, GISTs, breast, lung, prostate, ovarian and colorectal carcinomas (CRC). We aimed at determining the frequency of c-KIT expression and mutations in a series of 109 CRC cases (73 primary tumours and 36 lymph node metastases) characterised for KRAS and BRAF mutations. We also aimed at analysing the cellular effects of STI571/Gleevec in CRC-derived cell lines displaying c-KIT expression and KRAS or BRAF mutations. By immunohistochemistry, we found c-KIT overexpression in 15% (11/73) of primary tumours and in 14% (5/36) of metastasis; however, cases showing overexpression did not show c-kit mutations in hotspot regions. The majority (64%) of primary tumours with c-KIT overexpression had mutations at KRAS-BRAF genes. The same was true for 60% of the metastases. We treated CRC cell lines with STI571/Gleevec and verified that it inhibits proliferation and induces apoptosis in all cell lines. In conclusion, overexpression of c-KIT is observed in a subset of primary and CRC metastases in the absence of c-kit mutations. STI571/Gleevec increases apoptosis in CRC cell lines independently of its genetic profile, suggesting that STI571/Gleevec is likely to be an alternative drug for the clinical trials of CRC.
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PMID:A subset of colorectal carcinomas express c-KIT protein independently of BRAF and/or KRAS activation. 1748 4

Carney triad is a rare non-hereditary condition affecting young females and characterized by metachronous or synchronous occurrence of epithelioid gastrointestinal stromal tumours (GISTs), pulmonary chondroma and extra-adrenal paraganglioma. The genetic alterations in Carney triad-related GISTs have not been well studied. We evaluated GISTs from three females with incomplete Carney triad for KIT and PDGFRA mutations and studied the DNA by comparative genomic hybridization (CGH). All GISTs originated in the antrum and had a monotonous epithelioid morphology. Two patients had GISTs and pulmonary chondroma and one had GISTs and paraganglioma. Initial manifestation was GIST (n=1), pulmonary chondroma (n=1) and bladder paraganglioma (n=1). Time to the second component was 2-13 years. Two patients were alive at 108 and 168 months (one with metastases) and one died of the disease 3 years later. All cases were wild-type for KIT exons 9, 11, 13, 17 and PDGFRA exons 12 and 18. CGH revealed 14 aberrations (mean, 4.7/tumour) including 11 gains (X, 1q, 5p, 8q, 9p, 12p, 13q, 18p, 19q), 2 amplifications (1q, 19p) and one loss (13q). Carney triad-related GISTs do not only lack conventional KIT and PDGFRA mutations, but they also lack the non-random loss of 14q and 22q characteristic of their sporadic counterparts, suggesting an origin through a distinct pathogenetic pathway.
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PMID:Epithelioid gastric stromal tumours of the antrum in young females with the Carney triad: a report of three new cases with mutational analysis and comparative genomic hybridization. 1754 39

The introduction of imatinib has greatly improved the treatment options and quality of life of patients with gastrointestinal stromal tumors. Systemic treatment with imatinib alone most likely, however, does not cure the disease because, despite long-lasting major remissions, the majority of patients eventually relapse. Therefore, complete surgical resection remains the only curative approach in patients with gastrointestinal stromal tumors. Given a strong systemic treatment option at hand, the use of multimodal treatment strategies for patients with locally advanced or metastatic disease seems self-evident as many tumors become resectable after a treatment with imatinib. Few retrospective and no prospective data, however, are yet available on feasibility and the prognostic impact of these strategies, which represents a major challenge on how to decide on these patients in clinical practice. We therefore critically discuss the available evidence and current concepts for multimodal treatment of gastrointestinal stromal tumors and how modern diagnostics, such as KIT genotyping, may influence our clinical decision-making in this context.
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PMID:The challenge of opportunities: how far can and should we go with targeted treatments and modern diagnostics in gastrointestinal stromal tumors? 1762 42

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestinal tract. GISTs range from benign indolent neoplasms to highly malignant sarcomas. Gain-of-function mutations of tyrosine kinase receptors, KIT or PDGFRA, have been identified in most GISTs. In this study, we report 36 GIST patients whose tumors had homozygous KIT exon 11 mutations detected by direct sequencing of PCR products. Loss of heterozygosity in KIT locus and other chromosome 4 loci were documented in majority of these tumors. However, fluorescence in situ hybridization with KIT locus-specific probe and chromosome 4 centromeric enumeration probe showed no evidence of KIT hemizygosity in a majority of analyzed cases. These findings are consistent with duplication of chromosome 4 with KIT mutant allele. Homozygous KIT exon 11 mutations were found in 33 primary tumors and 7 metastatic lesions. In two cases, shift from heterozygosity to homozygosity was documented during tumor progression being present in metastases, but not in primary tumors. Among primary GISTs, there were 16 gastric, 18 intestinal and 2 from unknown locations. An average primary tumor size was 12 cm and average mitotic activity 32/50 HPFs. Out of 32 tumors 29 (90.6%) with complete clinicopathologic data were diagnosed as sarcomas with more than 50% risk of metastatic disease, and 26 of 29 patients with follow-up had metastases or died of disease. An average survival time among pre-imatinib patients, who died of the disease was 33.4 months. Based on these findings, we conclude that presence of homozygous KIT exon 11 mutations is associated with malignant course of disease and should be considered an adverse prognostic marker in GISTs.
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PMID:Presence of homozygous KIT exon 11 mutations is strongly associated with malignant clinical behavior in gastrointestinal stromal tumors. 1843 12

Molecular characterization of gastrointestinal stromal tumors (GISTs) plays an increasing role not only for the patient's prognosis but also for treatment options and in the context of resistance to therapy. Several mutational subtypes in KIT or platelet-derived growth factor receptor-alpha (PDGFRalpha) have been identified to be correlated with a different clinical behavior of GISTs. In KIT exon 11, deletions in the proximal part are associated with a high metastatic risk, whereas duplications in the distal part lead to a less aggressive phenotype. GISTs of the small bowel with a duplication in KIT exon 9 are often high risk tumors. In contrast, PDGFRalpha exon 18 mutated GISTs tend to have a low malignant potential. The authors suggest to include these molecular data together with classical parameters such as mitotic count and tumor size into the risk assessment of GISTs. The first choice for treatment of GISTs is still the surgical resection. In advanced tumors, which cannot be R0 resected, the neoadjuvant treatment with the tyrosine kinase inhibitor imatinib is now well established. Furthermore, an adjuvant treatment of locally R0-resected intermediate and high risk tumors is evaluated in several international clinical trials. For metastatic disease, treatment with imatinib is still the first option, but with new upcoming substances, the molecular characterization of GISTs may become mandatory. Very recently, it has been shown that sunitinib may be especially effective in GISTs with KIT exon 9 mutation, whereas these tumors show only an intermediate response to imatinib. A European Organisation for Research and Treatment of Cancer clinical trial randomizing patients according to their mutational status is under preparation. Secondary resistance to imatinib treatment is increasing, at least partly due to secondary mutations in the tyrosine kinase domain of the KIT receptor. Once a lesion has been shown to carry such a mutation, the local excision may be useful, mean while still responding metastases are further controlled by continuing imatinib. Taken together, the molecular characterization of GISTs turns out to play a central role before and during the treatment with tyrosine kinase inhibitors, which have improved the treatment of GIST patients dramatically.
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PMID:Mutation analysis of gastrointestinal stromal tumors: increasing significance for risk assessment and effective targeted therapy. 1770 Oct 51

Gastrointestinal stromal tumors (GISTs), the most common mesenchymal tumors in the gastrointestinal tract, metastasize in up to 50 % of cases and are resistant to conventional radio- and chemotherapy. They are characterized by the expression of the type III receptor tyrosine kinase KIT which is the most important diagnostic immunohistochemical feature. Genomically, the majority of GISTs carry heterozygous mutations in the KIT or the PDGF receptor alpha gene leading to an autophosphorylation of the respective receptor protein. The evaluation of the mutational status allows the subdivision of GISTs into different prognostic sub-groups. For example, GISTs carrying an activating mutation in PDGF receptor alpha are most often located in the stomach and seem to have a better prognosis than GISTs with a KIT mutation. Specific mutational subtypes of KIT mutations in exon 11 (esp. proximal deletions of codons tryptophane-557 and lysine-558) have a significantly higher metastatic risk than GISTs with KIT mutations located in the distal part of exon 11 (esp. insertions/duplications). GISTs in the small bowel most often carry KIT exon 9 mutations and have a worse prognosis than GISTs with exon 11 mutations. Mutational subtype in KIT or PDGF receptor alpha not only influences the biological behavior of GISTs but also their response to treatment with imatinib, a tyrosine kinase inhibitor also inhibiting ARG, PDGF receptor beta and BCR-ABL. KIT exon 11 mutated tumors show response rates of up to 80 % of cases whereas KIT exon 9 mutated GISTs respond in less then 50 %. GISTs without detectable KIT mutation in these both exons often are resistant to imatinib. The development of secondary resistance to imatinib in GIST patients occurs in up to 40% of cases and is partly due to secondary KIT mutations occuring additionally to the primary mutation. Actually, several studies evaluate the efficacy of alternative small molecules such as SU 11248, RAD001 and AMG706 inhibiting signal transduction pathways downstream of KIT and PDGF receptor alpha. In summary, mutational status in KIT or PDGF receptor alpha of GISTs is relevant for prognosis, for response to treatment and for further insights into mechanisms of treatment failure.
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PMID:[Therapeutic targets in gastrointestinal stromal tumors]. 1786 82

Primary and metastatic so-called malignant fibrous histiocytoma/undifferentiated high-grade pleomorphic sarcoma (MFH) is rare in the gastrointestinal (GI) tract with approximately 50 primary and five metastatic cases reported so far. We evaluated two primary gastric and three metastatic intestinal high-grade pleomorphic sarcomas with features of storiform-pleomorphic MFH. Gastric tumours occurred in a 79-year-old man and a 68-year-old woman. One patient died post-operatively, and the other was disease-free at 6 months. Three patients presented with GI metastasis 24, 60 and 0 months after diagnosis of MFH of the heart (n = 1) and the thigh (n = 2). Metastases were located in the small (n = 1) and large bowel (n = 2) and were characteristically pedunculated and polypoid with oedematous haemorrhagic stroma. Concurrent metastases (brain, lung, bone) were present in all three cases. Tumours expressed alpha-smooth muscle actin (four of five), platelet-derived growth factor receptor (PDGFR) alpha (three of three) and PDGFRbeta (two of three) but were negative for CD117, CD34 and other lineage-specific markers. Ultrastructural examination revealed myo/fibroblastic features. Both gastric MFH were wild type for KIT and PDGFRalpha. In conclusion, primary and metastatic MFH of the GI tract commonly express PDGFRalpha and show a myo/fibroblastic phenotype. They should be distinguished from a variety of primary and metastatic pleomorphic neoplasms, in particular high-grade sarcomatous GI stromal tumours (GIST), pleomorphic leiomyosarcoma, sarcomatoid carcinoma and other mimics.
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PMID:Primary and metastatic high-grade pleomorphic sarcoma/malignant fibrous histiocytoma of the gastrointestinal tract: an approach to the differential diagnosis in a series of five cases with emphasis on myofibroblastic differentiation. 1787 30

Germ-line mutations in the KIT receptor tyrosine kinase gene have been described in families with a propensity to develop gastrointestinal stromal tumor (GIST). There is limited information from large kindreds regarding median age at diagnosis, detailed histopathology, clinical effects of imatinib therapy and chromosomal abnormalities of the KIT gene. We identified a large kindred with GIST. Each family member was interviewed and appropriate medical records and radiographic imaging were obtained. Archival tumor tissue was obtained to confirm diagnosis, extract genomic DNA and perform fluorescent in situ hybridization cytogenetics of the KIT gene. Fifteen of 79 individuals with GIST were identified in this kindred. There were 8 males, the mean age at diagnosis was 53.9 (range 45-71) years. Histopathology revealed microscopic proliferation and nodularity in the myenteric plexus, spindled morphology, diffuse Kit but variable CD34 staining and low mitotic rates in the setting of metastatic disease. A deletion of codon 579 in exon 11 of the KIT gene was identified in tumor and normal tissue of this family. Mutation and cytogenetic analysis revealed homozygous loss of the wild-type KIT sequence in tumor from one individual. Four of 4 individuals treated with imatinib are alive and without progression while 9 of 11 individuals not treated with imatinib are deceased. This study describes a kindred with a propensity to develop GIST in an autosomal dominant pattern. Germ-line deletion of KIT codon 579 in GIST is associated with clinical benefit from imatinib, limited utility of mitoses to predict malignant potential, and a novel homozygous deletion of this codon in one individual.
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PMID:Clinical, histopathologic, molecular and therapeutic findings in a large kindred with gastrointestinal stromal tumor. 1794 34

We report on a patient with rectal malignant melanoma. The patient was a 40-year-old man who complained of anal bleeding. His grandmother had died of pancreatic cancer and his mother had been operated for rectal cancer. Physical examination revealed a hard mass at the 12 o'clock position, 2 cm from the anal verge. A colonoscopic examination revealed an irregular surface mass, approximately 4.0 cm in size, located on the anterior wall of the lower rectum. A biopsy of the rectal tumor showed the proliferation of epithelioid cells with pleomorphic features. Immunohistochemical analysis was performed. S-100 protein, CD-56, and KIT expression were positive, but HMB-45 expression was negative. Abdominopelvic computed tomography (CT) revealed multiple liver and lymph node metastases. With the diagnosis of neuroendocrine carcinoma of the rectum, abdominoperineal resection was performed. After the operation, the serum lactate dehydrogenase level had rapidly increased. An abdominal CT showed progressive liver metastases. Thirteen days after the surgery, abdominal angiography was performed, which showed multiple hypervascular tumor stains in the liver. The reservoir was implanted transcutaneously with the aid of angiography and the catheter was fixed to the proper hepatic artery. Neoadjuvant chemotherapy using cisplatin and irinotecan via the subcutaneous reservoir port was performed and a partial response was obtained. However, the final pathological diagnosis of the surgically resected specimen was malignant amelanotic melanoma of the rectum. Immunohistochemical expression differed between rectal biopsy specimens and surgically resected specimens. HMB-45 expression was positive and KIT expression was negative in the resected specimen. As preoperative pathological diagnosis showed rare rectal tumor, we measured the chemosensitivity of the rectal tumor using the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) to determine the most appropriate chemotherapy regimen for the patient. However, there were no anticancer drugs tested by CD-DST for malignant melanoma. With informed consent, the patient received two cycles of immunochemotherapy consisting of dacabazine, nimustine hydrochloride, vincristine sulfate, and interferon -beta. Although the patient was treated with immunochemotherapy for metastatic liver tumor, he died because of progression of metastases.
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PMID:Case of rectal malignant melanoma showing immunohistochemical variability in a tumor. 1796 34


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