Surgical resection for gastric GIST with multiple liver metastases after imatinib therapy

Advanced gastrointestinal stromal tumor (GIST) with multiple liver metastases was successfully resected after pharmacological debulking with imatinib. A 47-year-old man with a huge gastric GIST with multiple liver metastases considered irresectable was administrated 400 mg/day of imatinib. The tumor responded dramatically but a resistant clone appeared 8 months later. A small mass was detected inside one of the liver lesions that had changed to a shrunken cystic mass. In subsequent surgery, we successfully treated all tumors with total gastrectomy, partial hepatic resection, and hepatic radiofrequency abrasion (RFA). The resected specimen showed viable cells of a new liver lesion. Genetic analysis of the tumor revealed 2 mutations in KIT gene and 1 mutation in platelet-derived growth factor receptor-α (PDGFRA) gene. Since only surgery can potentially cure the disease, advanced GIST patients on imatinib therapy should be closely monitored for resistant lesions and surgery should be considered repeatedly to improve outcome.