الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of gastrointestinal tract (1 - 3% of all gastrointestinal malignancies) they are typically defined as tumors whose behavior is driven by mutation in the Kit gene or PDGFRA gene. About 70% of GIST occurs in stomach, 20% in small intestine and less than 10% in esophagus. Small tumors are generally benign, especially when cell division rate is slow, but large tumors disseminate to the liver, omentum and peritoneal cavity, they rarely occur in other abdominal organs. GISTs are thought to arise from interstitial cells of Cajal (ICC). Surgery may be used as initial therapy to completely remove the primary tumor and may also be used to remove metastatic tumors. Patients with more advanced disease may undergo targeted therapy followed by surgery once they have responded to treatment. This approach may allow some patients who were initially diagnosed with inoperable disease to undergo surgery once their cancer has responded to the targeted therapy. Laparoscopic surgery is generally not advised unless the GIST is smaller than 2 cm. KIT is the most common tumor marker for GIST, with 95% of GISTs staining positive for KIT. Tyrosine kinase inhibitors (TKIs) are now accepted as effective systemic treatments for KIT+ GIST. They are used as adjuvant therapy after surgical resection and for the treatment of unresectable and/or metastatic disease. TKIs inhibit the phosphorylation (activation) of KIT kinase, thus blocking oncogenic signaling related to KIT mutations. The most recent practical guidelines issued by the National Comprehensive Cancer Network (NCCN) support the use of certain TKIs as Neoadjuvant treatment, to reduce the size of potentially resectable GISTs, Adjuvant treatment, to reduce the risk of recurrence after resection. Systemic treatment to slow the progression of unresectable and/or metastatic disease. Despite the proven success of imatinib and other newer tyrosine - kinase inhibitors, surgical resection remains the treatment of choice and offers the only chance for cure from GIST.