Predicted imatinib response and GIST characteristics based on the mutation of the primary tumor in the KIT or PDGFRA genes.
to Imatinib *
|KIT gene||80-85%||mostly spindle|
|Wild Type adult GIST c|
(no KIT or
|any type||any site|
|* reported as "clinical benefit" including response or stable disease based on combined data from 3 clinical trials: B2222, EORTC phase I-II, EORTC Phase III.|
|a Rarely gastric GIST can be exon 9. About a third of small intestinal GISTs are exon 9 mutant (remainder are exon 11).|
|b Few data available.|
c Pediatric/adolescent GISTs are usually wild-type but differ from adult wild-type GISTs in terms of histology and drug responsiveness.