Adjuvant Imatinib or Observation in Patients With Gastrointestinal Stromal Tumors With <i>KIT</i> Exon 9 Mutations

In this large international cohort study of resected GISTs with KIT exon 9 mutations, adjuvant imatinib was independently associated with delayed recurrence and improved survival. These findings support the use of adjuvant imatinib in mNIH high-risk GISTs with KIT exon 9 mutations and underscore the need for prospective studies to define optimal dosing and treatment duration.