title: Molecular analysis of c-Kit and PDGFRA in GISTs diagnosed by EUS.
abstract: Gastrointestinal stromal tumors (GISTs) are characterized by overexpression and mutations of c-Kit. Approximately 80% of c-Kit mutations occur in exon 11, being a response factor to imatinib (Gleevec) therapy. Mutations of platelet-derived growth factor receptor-alpha (PDGFRA) are observed in a subset of GISTs lacking c-Kit mutations.We aimed to assess whether c-Kit and PDGFRA mutation analysis of GISTs obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) could be routinely performed. Mutation analysis of c-Kit hotspot exons (9, 11, 13 and 17) and PDGFRA hotspot exons (12 and 18) was performed in aspirates of 33 GISTs and 18 non-GIST mesenchymal tumors. Of the GIST cases, 19 (58%) of 33 contained a mutation in exon 11, 1 (3%) in exon 9, and none in exons 13 and 17. No activating c-Kit mutations were identified in non-GIST cases. No PDGFRA mutation was detected. Mutation analysis is possible in these FNA cell blocks and can assist in the diagnosis and therapeutic decisions in GIST cases/
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Gomes
authors.forename: Ricardo H
authors.initials: RH
authors.lastname: Bardales
authors.forename: Fernanda
authors.initials: F
authors.lastname: Milanezi
authors.forename: Rui M
authors.initials: RM
authors.lastname: Reis
authors.forename: Fernando
authors.initials: F
authors.lastname: Schmitt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D001483:Base Sequence; D044963:Biopsy, Fine-Needle; D019160:Endosonography; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000737:chemistry* / Q000000981:diagnostic imaging* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis* / Q000235:genetics; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000032:analysis* / Q000235:genetics
chemical_list: D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha