title: Genetic and pathologic characteristics of gastrointestinal stromal tumors in extragastric lesions.
abstract: The goal of this study was to investigate differences in the clinicopathologic and genetic characteristics of gastric and extragastric gastrointestinal stromal tumors (GISTs). We evaluated 13 extragastric GISTs and compared them with 56 gastric GISTs, which were described previously. DNA was extracted from paraffin-embedded tumor specimens, and exons 9, 11, 13, and 17 of the KIT gene and exons 12 and 18 of the platelet-derived growth factor receptor alpha (PDGFRA) gene were amplified by polymerase chain reaction and sequenced. Immunohistochemistry was performed for KIT, CD34, Ki-67 (as a marker of cell proliferation), and CD31 (as a marker of microvessel density), and apoptosis was assessed by in situ DNA nick end-labeling. Of the 13 extragastric GISTs 7 (54%) had a mutation in exon 11 of KIT, and 2 (15%) had a mutation in exon 13 of KIT. Deletions in exon 11 of KIT were the most common mutation encountered in the extragastric GISTs. The extragastric GISTs, especially small intestinal GISTs, showed larger deletions, leading to deletions of amino acid residues in the KIT protein, and higher vascularity than did the gastric GISTs. These data suggest that extragastric GISTs differ from gastric GISTs with respect to associated mutations and angiogenic activity.
authors.affiliation: Department of Medicine and Molecular Science, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima 734-8551, Japan.
authors.forename: Songde
authors.initials: S
authors.lastname: Cho
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kitadai
authors.forename: Shigeto
authors.initials: S
authors.lastname: Yoshida
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshihara
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D018952:Antigens, CD34 / Q000032:analysis; D017209:Apoptosis; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D005091:Exons / Q000235:genetics; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D017353:Gene Deletion; D006801:Humans; D007150:Immunohistochemistry; D007414:Intestinal Neoplasms / Q000098:blood supply / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009389:Neovascularization, Pathologic / Q000473:pathology; D016133:Polymerase Chain Reaction; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis / Q000235:genetics; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics; D012004:Rectal Neoplasms / Q000098:blood supply / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D019394:Ki-67 Antigen; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha