GIST (gastrointestinal stromal tumor)
GIST (gastrointestinal stromal tumor)
Overview Definition and Incidence Clinical diagnosis Pathology Risk assessment Etiology KIT signalling Conclusions
Ls GIST: Definition Most frequent mesenchymal neoplasms in the Gl tract Highest incidence among group aged 50-65 years Up to 50%of GIST recur and/ or metastasize 5-years survival rate (historically)30 to 40% Up to 90%of GIST carry K/T or Pdgfra mutations 90% stain positive for KIT 1. Miettin en M et al. Virchows Arch. 2001: 438: 1-12 Courtesy W3 Hofmarin, Memmingen, Germany
56yr old female, upper GI bleeding w mor extramucosal tumor, biopsy: spindle cel/tu Case 4 Type DERIVED/PRIMARYIAXIAU/CT Type ORIGINAUPRIMAF Refphys GasH RepLy
Non-Responder to Imatinib, no Symptom Relief, Gastrectomy Histology: PECOMA
os Overview Definition and incidence Clinical diagnosis Pathology Risk assessment Etiology KIT signalling Conclusions
Ls GIST Diagnosis: Imaging Computed Tomography (CT) Endoscopic Ultrasound (US) Magnetic Resonance Imaging (MR|) 18F-FDG Positive Emission Tomography(PET) Dynamic Contrast-Enhanced Ultrasonography (DCE-US) Fletcher CD et al. Hum Path ol 2002 33: 459-465 Miettinen met al. mod path ol 2000: 13: 1134-1142 84 Lassau N et al. Am J Roentgeno. 2006: 187(5): 1267-73
GIST: Biopsy Preoperative biopsy of a resectable mass is commonly performed but is associated with risks Biopsy is necessary if: Suspecting another cancer such as lymphoma or other sarcoma Considering neoadjuvant therapy or therapy for metastatic disease Casali et al. Ann On col 2008; 19(suppl 2): 1135-1i38 Demetri et al. J Natl Compr Can c Netw. 2007: 5(suppl 2) S1-29
GIST: Biopsy EUS-FNA(Endoscopic ltrasound -fine needle aspiration) EUs to determine size and extent of submucosal lesions FNA not consistently useful Core Biopsy Risk of dissemination unconfirmed Lachter et al. Hepatogastroenterology. 2008: 55(86-87): 1653-6
os Overview Definition and Incidence Clinical diagnosis Pathology Risk assessment Etiology KIT signalling Conclusions