Gastrointestinal stromal tumors with an uncommon primary mutation responded well to imatinib

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, driven by mutations in the proto-oncogene c-KIT or platelet-derived growth factor alpha (PDGFRA) gene in 85%-90% of cases. 3Other mutations are rare and have unknown clinical effects.Imatinib, a tyrosine kinase inhibitor (TKI), is used as a first-line treatment and confers a median survival of up to 5 years in 70%-85% of patients with advanced GISTs. 3 This response correlates with the tumor's mutational status.Exon 11 mutations are correlated with a good response, whereas mutations in exons 9, 13, and 17 may result in variable responses to imatinib.Insufficient data