[Multidisciplinary Treatment for High-Risk GIST of the Stomach]

A 59-year-old man underwent total gastrectomy(with D2 dissection)and cholecystectomy for gastric cancer and a submucosal tumor of the stomach. The specimen was immunohistochemically positive for c-kit, the Ki-67 label index was 10%, and the mitotic count was 20/HPF. Finally, the patient was diagnosed with high-risk gastrointestinal stromal cancer with normal type gastric cancer. After discharge from hospital, we started administration of TS-1 as adjuvant therapy for the gastric cancer. As multiple recurrences of the GIST in the abdomen developed, the patient underwent 3 radical local resections. Mutational analysis revealed a PDGFRA mutation in exon 18, which causes resistance to both imatinib and sunitinib. As he was refractory to imatinib, the patient received regorafenib. After a while, it caused liver failure, which required 7 rounds of plasmapheresis. The patient died from multiple organ failure resulting from multiple recurrences 4 years after the first surgery.