Table 2.

Correlation of activating mutations with response to imatinib and progression-free survival in GIST patients

Tyrosine kinase (exon)*ProductMutation typesFrequency in GISTs (%)Primary locationPartial response (%)Median PFS
KIT(43, 44)
    Exon 11Portion of the cytoplasmatic juxtamembrane domainDeletion/insertion of codons 557 and 559 and point mutations: codons 557, 559, 560, and 57666–71Mainly stomach83.523 mo
    Exon 9Region located in the extracellular domainAY501-502 duplication/insertion or FAF506-508 duplication/insertion10–18Small bowel in 90-95% of cases47.87 mo
    Exon 13First part of the split tyrosine kinase domainPoint mutation K642E1–4Not defined100NA
    Exon 17Phosphotransferase domain (TK II domain)Point mutations N822H, N822K, D816V1–4Not defined50NA
PDGFRα(10, 43, 44)
    Exon 12Juxtamembrane domainPoint mutation V561D1–2Only stomach66.7NA
    Exon 18TK II domainPoint mutation D842V2–6Only stomach0NA
Wild type(43, 44, 48)1–12Stomach or omentum/mesentery03 mo
  • Abbreviations: PFS, progression-free survival; NA, not available.

  • * Numbers in parentheses are reference citations.

  • This data should be considered with caution because of the small number of reported cases.