Advanced or metastatic gastrointestinal stromal tumors: systemic treatment options.

Gastrointestinal stromal tumor (GIST), the most common sarcoma arising in the gastrointestinal tract, typically expresses the tyrosine-kinase receptor, C-KIT, and contains activating mutation in the c-kit or platelet-derived growth factor receptor (pdgfr) gene. Recently, development of small molecules that inhibit the kinase activity of mutant C-KIT and PDGFR proteins has radically changed treatment and prognosis of patients diagnosed with advanced GIST as this molecularly "targeted" therapy has demonstrated remarkable high-level of activity in this disease.