The big, the bad, and the exon 11: adjuvant imatinib for all gastro-intestinal stromal tumors or just the ugly?

Gastrointestinal stromal tumor (GIST), a type of sarcoma, is the most common mesenchymal tumor of the gastrointestinal tract. Because the majority of GIST is driven by KIT proto-oncogene receptor tyrosine kinase (KIT) (encodes KIT protein) (OMIM 164920) and platelet-derived growth factor receptor α (PDGFRA) (encodes platelet-derived growth factor receptor α) (OMIM 173490), it represents a paradigm for targeted therapy in solid tumors. An exploratory analysis of the Scandinavian Sarcoma Group (SSG) XVIII/Arbeitsgemeinschaft Internistische Onkologie (AIO) trial was recently published by Joensuu et al. (1). The parent trial, originally published in 2016, compared 3 years to 1 year of adjuvant imatinib (Gleevec^®) in surgically resected GISTs (2). It established 3 years of adjuvant imatinib as the standard of care for high risk GIST. The authors, hoping to capitalize on lessons learned about the molecular biology of this disease, evaluated the mutation status of patients enrolled in the trial.