Resistance development during long-term treatment with Imatinib of patients with recurrent and/or metastatic gastrointestinal stromal tumors – single center experience

Aims: Gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors of the gastrointestinal tract. They are supposed to arise from Cajal cells because of gain-of-function mutations of the tyrosine receptor kinases kit or PDGF-R. The small molecule Imatinib selectively inhibits the kinase activity of both receptors and has been used successfully in the treatment of GIST since 2001. However, increasingly resistance against Imatinib has been reported with a mean time to progression of 24 months. Here we report our experience in treatment of relapsed or metastasized GIST. Patients: Fourteen consecutive patients…