Complete response to second-line chemotherapy with sunitinib of a gastrointestinal stromal tumor: A case report

Gastrointestinal stromal tumors (GISTs) are a type of sarcoma, and the most common mesenchymal tumor of the gastrointestinal tract. Systemic chemotherapy is recommended for unresectable or metastatic GISTs. Imatinib is an oral multitargeted receptor tyrosine kinase inhibitor that is effective as adjuvant chemotherapy for primary high-risk cases, and as palliative chemotherapy for unresectable or metastatic cases. For imatinib-resistant cases, second-line chemotherapy with sunitinib is recommended due to significantly longer median progression-free survival and higher response rates compared with a placebo. A 54-year-old woman presented with persistent upper abdominal pain and anorexia. An upper gastrointestinal endoscopy and computed tomography revealed a submucosal tumor of the stomach with no apparent metastases. The patient underwent total radical gastrectomy, and was diagnosed histologically with high-risk GIST for recurrence, therefore, the patient received adjuvant chemotherapy with imatinib. However, multiple liver and lymph node metastases were detected, and the patient received sunitinib therapy. After four cycles of sunitinib, the liver and lymph node metastases disappeared, and a complete response (CR) was achieved. To date, there have been no cases of CR in the prospective clinical trials examining the effects of sunitinib, or in case reports worldwide. Therefore, this is a very rare case report of a patient with metastatic GISTs who achieved CR with sunitinib as second-line chemotherapy.