Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0000737 (abdominal pain)
 31,184 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Imatinib mesylate (imatinib) is an orally administered competitive inhibitor of the tyrosine kinases associated with the KIT protein (stem cell factor receptor), ABL protein and platelet-derived growth factor receptors. The KIT tyrosine kinase is abnormally expressed in gastrointestinal stromal tumour (GIST), a rare neoplasm for which there has been no effective systemic therapy. In a randomised, nonblind, multicentre study that evaluated imatinib 400 or 600mg once daily in 147 patients with advanced GIST, confirmed partial responses were achieved in 54% of patients overall (median duration of follow-up was 288 days). Stable disease was experienced by 28% of patients and the estimated 1-year survival rate was 88%. Similar response rates were reported in a smaller, dose-escalation study, in which objective tumour response was a secondary endpoint. Although nearly all patients with GIST treated with imatinib experienced adverse events, most events were mild or moderate in nature. Severe or serious adverse events occurred in 21% of patients in the larger study, and included gastrointestinal or tumour haemorrhage. The control of cellular processes, such as cell growth, division and death, involves signal transduction, which commonly involves the transfer of phosphate from adenosine triphosphate (ATP) to tyrosine residues on substrate proteins, by tyrosine kinase enzymes. Activation of oncogenes coding for kinase proteins can lead to the production of kinases that are continually active in the absence of a normal stimulus,leading to increased cell proliferation and/or decreased apoptosis. A major focus of cancer research in recent years has been to identify oncogenic molecules and the signal transduction pathways in which they are involved, in order to develop specifically targeted drugs. One such drug is imatinib mesylate (imatinib, Glivic/Gleevec), an orally administered 2-phenylaminopyrimidine derivative that is a competitive inhibitor of the tyrosine kinases associated with platelet-derived growth factor (PDGF) receptors, the Abelson (ABL) protein and the KIT protein (also known as stem cell factor [SCF] receptor). Imatinib was initially evaluated for the treatment of chronic myeloid leukaemia (CML) [reviewed previously in Drugs]. More recently, imatinib has been approved for the treatment of patients with advanced gastrointestinal stromal tumour (GIST), in which KIT, a tyrosine kinase receptor, is abnormally expressed. GISTs are soft tissue gastrointestinal sarcomas probably arising from mesenchymal cells. They are rare neoplasms, with between 5000 and 10 000 new cases being diagnosed each year in the US. GISTs occur throughout the gastrointestinal tract but the stomach and small intestine are the most common sites. Symptoms depend on the site and size of the tumour, and may include abdominal pain, gastrointestinal bleeding or signs of obstruction; small tumours may be asymptomatic. The diagnosis of GIST is made by immunohistochemical staining for CD117, a cell surface antigen on the extracellular domain of KIT, in conjunction with pathological examination of tissue with light microscopy. All GISTs may have some degree of malignant potential. They are unresponsive to standard chemotherapy and to radiotherapy, and the mainstay of treatment in the past has been surgery. However, recurrence rates are high, and there has been no effective systemic treatment for unresectable GIST or metastatic disease. For patients in whom complete resection is not possible, or in patients with metastatic or recurrent disease, the median duration of survival is 9-12 months, and 10-19 months, respectively. Gain-of-function mutations of the KIT proto-oncogene occur in up to 90% of GISTs, allowing constitutive activation of tyrosine kinase (i.e. auto-phosphorylation of tyrosine residues independent of ligand-receptor binding), leading to aberrant cell division and tumour growth. Imatinib selectively inhibits the tyrosine kinase activity associated with KIT, which forms the rationale for evaluating its effects in GIST. Subsequent to initial evidence of the clinical efficacy of imatinib in a single patient with progressive, metastatic, CD117-positive GIST, formal studies of imatinib in this new indication were initiated. This article summarises the pharmacology, efficacy and tolerability profile of imatinib in the treatment of patients with advanced GIST.
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PMID:Imatinib mesylate: in the treatment of gastrointestinal stromal tumours. 1260 Feb 28

Three cases of gastrointestinal stromal tumors (GIST) are reported as typical examples of the broad clinical spectrum in which these rare tumors can be detected. The first case describes an 82-year-old patient with a hemorrhagic shock due to upper gastrointestinal bleeding from a GIST of the stomach. GIST most frequently present with either gastrointestinal bleeding, abdominal pain or a detectable mass on physical examination or by ultrasound imaging. Clinically asymptomatic tumor growth also occurs as demonstrated by the second case of a 44-year-old -woman with an incidental finding of GIST during surgery of the esophagus. The cases are used to discuss the consequences for therapy and prognosis resulting from the heterogeneity of this tumor entity; the relevant immunohistochemical markers used to distinguish between various tumor subtypes of gastrointestinal mesenchymal tumors (GIMT) are listed. Since gastrointestinal stromal tumors (GIST) represent the most common subgroup of GIMT, we focus on the clinicopathological prognostic factors of GIST. The third case of a 40-year-old patient with a malignant GIST recurrence after surgery and exhibiting secondary resistance after one year of successful therapy with the receptor tyrosine kinase inhibitor imatinib (Gleevec), antagonizing pathogenetically relevant constitutive c-KIT activation, illustrates the potential and limitations of the only effective drug treatment for advanced GIST.
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PMID:[Gastrointestinal stromal tumors: a broad clinical spectrum from incidental -discovery to acute gastrointestinal bleeding]. 1502 11

This case report presents an incidental finding of a rectal GIST (gastrointestinal stromal tumor) presenting as a submucosal calculus, not previously reported. A 53-year-old man without a significant medical history presented with abdominal pain in the left lower quadrant, and with constipation. Upon rectal examination, a hard submucosal swelling was palpated 4 cm from the anus, at 3 o'clock, in the left rectum wall. X-ray photos, computerized tomography (CT)-scan and a magnetic resonance imaging (MRI) scan clearly showed a calculus. Excision revealed a turnip-like lesion, 3.1 x 2.3 x 1.8 cm. Analysis showed it was a rectal GIST, a rare mesenchymal tumor of the gastrointestinal tract, which expressed CD117 (or c-kit, a marker of kit-receptor tyrosine kinase) and CD34. Calcification is not a usual clinicopathological feature of GISTs [1-3], and although a number of rectal GISTs have been reported [4-9], we have found no cases so far of rectal GIST presenting as a submucosal calculus. In general, GISTs are rare mesenchymal tumors of the gastrointestinal tract (nerve tissue, smooth muscle). Histology and immunohistochemistry discriminate gastrointestinal stromal tumors from leiomyomas and neurinomas. The most important location is the stomach; the rectal location is rare. Usually, the classic signs of malignancy such as cellular invasion and metastasis are missing. A set of histologic criteria stratifies GIST for risk of malignant behavior such as mitotic activity and tumor size, cellular pleomorphism, developmental stage of the cell and quantity of cytoplasma [7,13]. Tumors with a high mitotic activity and size above 5 cm are considered malignant. Recent pharmacological advances such as tyrosine kinase inhibitors have determined c-kit (i.e., CD117) as the most important marker, amongst others. C-kit positive tumors respond extremely well to chemotherapy with Imatinib (Glivec, Gleevec) [10-12].
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PMID:Rectal GIST presenting as a submucosal calculus. 1726 37

On December 19, 2008, the U.S. Food and Drug Administration approved imatinib mesylate tablets for oral use (Gleevec(R); Novartis Pharmaceuticals Corporation, East Hanover, NJ) for the adjuvant treatment of adult patients following complete gross resection of Kit(+) (CD117(+)) gastrointestinal stromal tumor (GIST). A randomized, double-blind, placebo-controlled study enrolling 713 patients was submitted. The primary objective of the clinical trial was to compare the recurrence-free survival (RFS) intervals of the two groups. Overall survival (OS) was a secondary endpoint. Eligible patients were > or =18 years of age with a histological diagnosis of GIST (Kit(+)), resected tumor size > or =3 cm, and a complete gross resection within 14-70 days prior to registration. Imatinib, 400 mg orally, was administered once daily for 1 year. The study was terminated after completion of the third protocol-specified interim analysis. At that time, 100 RFS events were confirmed by a blinded central independent review. With a median follow-up of 14 months, 30 RFS events were observed in the imatinib group and 70 were observed in the placebo group (hazard ratio, 0.398; 95% confidence interval, 0.259-0.610; two-sided p-value < .0001). OS results are immature. Most patients in both groups experienced at least one adverse reaction, and 31% of the imatinib group and 18% of the placebo group experienced grade > or =3 adverse reactions. The most frequently reported adverse reactions (> or =20%) were diarrhea, fatigue, nausea, edema, decreased hemoglobin, rash, vomiting, and abdominal pain. Drug was discontinued for adverse reactions in 17% and 3% of the imatinib and placebo-treated patients, respectively.
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PMID:Approval summary: imatinib mesylate in the adjuvant treatment of malignant gastrointestinal stromal tumors. 2020 41

Although their overall incidence is low, GISTs are distinctive subgroup of gastrointestinal mesenchymal tumors which express CD117 or platelet derived growth factor receptor alpha (PDGFRA). Considered as rare digestive cancers, tumors like schwannomas, neurofibromas, gastrointestinal leiomiomas are now reclassified as GIST based on immunohistochemistry studies. GIST are more frequent in stomach (40-70%), small bowel (20-40%), colon (5-15%), meanwhile locations such as mesentery, omentum, retro peritoneum in less of 5%. 10 GIST patients were surgically managed during 2004-2009. 5 gastric and 5 small bowel GIST. Most with symptomatic disease: palpable tumor, abdominal pain, anemia, fatigue, superior digestive hemorrhage or occlusion. Imagistic diagnosis consisted of: barium swallow, abdominal sonography, CT and PET-CT. Confirmation was made by hystopathological exam and immunohistochemistry. All patients had more or less wide surgical resections. For some patients there was also a specific adjuvant treatment. All patients survived after surgery. The principle of surgery for GIST is RO resection of the tumor. Tumor rupture or R1 resection of the primary tumor has a negative impact on disease free survival. Some patients (great volume tumors, R1 or R2 resection) had adjuvant treatment. Imatinib mesylate and derivates showed a significant improvement of recurrence free survival with one condition: permanent treatment. Surgery remains the mainstay of treatment in patients with localized, resectable GIST. Recurrence rate of 17-21% and 5 years survival rate of 48-70%, even in resectable GIST, impose an adjuvant treatment.
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PMID:[Gastrointestinal stromal tumor (GIST)--medical rarities?]. 2094 86

Imatinib mesylate has been associated with the changes in bone turnover. We report a case of the development of tissue calcification in a patient on long-term therapy with this drug. A 48-year-old male patient with gastrointestinal stromal tumor and liver metastasis complained of abdominal pain. His treatment included hepatic artery chemoembolization and partial hepatectomy in addition to chronic imatinib mesylate for 4 years. On physical examination, he had a peritoneal mass just beneath the laparotomy incision scar that, after resection, was found to be dystrophic bone formation. Based on the previous studies suggesting bone changes due to chronic therapy with imatinib mesylate, we believe that the patient's new bone formation was causally related to the use of this drug. To our knowledge, there are no similar reported cases in the literature.
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PMID:Soft tissue calcification secondary to imatinib mesylate in a patient with gastrointestinal stromal tumor. 2367 9

Imatinib (Gleevec) is a biological agent that is approved for the treatment of chronic myeloid leukemia (CML) as well as gastrointestinal stromal tumor (GIST). The most frequently seen adverse effects in patients treated with imatinib include superficial edema, muscle cramps, musculoskeletal pain, rash, fatigue, headache, abdominal pain, and joint pain. Ototoxicity has rarely been reported except in two cases. We report a case of bilateral irreversible sensorineural hearing loss (SNHL) caused by imatinib in a patient receiving this agent in the adjuvant setting. This case underlines the importance of early recognition of this potential toxicity that can impact the quality of life.
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PMID:Imatinib-induced Ototoxicity in a Patient with Gastrointestinal Stromal Tumor (GIST). 2790 36

Gastrointestinal stromal tumors (GISTs) are the most common type of mesenchymal neoplasm of the gastrointestinal tract but consist of only 1% of all primary gastrointestinal neoplasms. Differentiated from other spindle cell tumors, GISTs are uniquely positive for CD117 expression which allows for molecular targeting therapy with imatinib mesylate (Gleevec). Clinical presentations are variable, ranging from asymptomatic to vague symptoms of abdominal pain, early satiety, abdominal distention or gastrointestinal bleeding. Very rarely, patients can present with tumor-bowel fistula and intra-abdominal abscesses. In this article, we discuss a rare presentation of a middle-aged male with multiple liver abscesses found to have a primary small bowel GIST. This patient received prompt intravenous antibiotics; however, hepatic abscesses can be easily misinterpreted as cystic hepatic metastases which can delay appropriate therapy. Streptococcus anginosus was found to be responsible for the formation of the liver abscesses visualized on computed tomography (CT) scan. Similar to Streptococcus bovis, knowledge in the literature is arising about the association between S. anginosus and gastrointestinal malignancies. This case highlights the importance of identifying concomitant primary GISTs with intra-hepatic abscesses, as these lesions can be easily misconstrued as liver metastases and consequently mismanaged. We herein emphasize that hepatic abscesses are a potential sequela of GISTs and should thus prompt further investigation for potential malignancies, if warranted, so that there is no delay in treatment of these gastrointestinal tumors.
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PMID:Small Bowel Gastrointestinal Stromal Tumor as a Gateway for Streptococcus anginosus Causing Multiple Liver Abscesses. 3249 19