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Medline ® Abstract for Reference 57

of 'Epidemiology, classification, clinical presentation, prognostic features, and diagnostic work-up of gastrointestinal mesenchymal neoplasms including GIST'

C-kit gene abnormalities in gastrointestinal stromal tumors (tumors of interstitial cells of Cajal.
Sakurai S, Fukasawa T, Chong JM, Tanaka A, Fukayama M
Jpn J Cancer Res. 1999;90(12):1321.
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the GI tract, and expresses KIT and CD34 in most cases. Gain-of-function mutation of the c-kit proto-oncogene has been described, but its significance in GIST has not yet been fully evaluated. Mutation in exon 11 of the c-kit gene was determined by both polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing in primary and metastatic GISTs and esophageal leiomyomas in Japanese subjects. C-kit gene mutation was identified in 15 of 48 primary GISTs (31%), four of seven metastatic GISTs, but none of the leiomyomas. Three mutations were mis-sense point mutations, and 16 were in-frame deletions of 3-48 bp. C-kit gene mutation was observed equally in low- and high-risk groups, and was not related to any clinical and pathologic factors, phenotypes or Ki-67 labeling index (LI) of tumor cells. In five of 15 deletion mutations (four in primary tumors and one in a metastatic tumor), the mutations were present at the distal location of exon 11 of the c-kit gene, which was a minor mutation in previous reports from Finland and the USA. C-kit gene mutations in GIST are not always related to a poor prognosis, but further comparative studies are necessary in Western and Japanese populations.
Department of Pathology, Jichi Medical School, Kawachi-gun, Tochigi. ssakurai@jichi.ac.jp