Surgical treatment for gastric GIST with special reference to liver metastases.

Background/Aims: Gastrointestinal stromal tumor (GIST) is recently defined as a tumor expressing c-kit and sometimes showing liver metastasis. We investigated the outcomes of gastric GIST with special attention to the effect of repeated treatment for the patients with liver metastases. Methodology: Fourteen gastric GISTs were retrospectively reviewed and the significance of the NIH stratification system was examined. Results: Liver metastasis was found in 4 of the 14 patients with gastric GISTs. Three of the 4 patients had metachronous liver metastases and underwent repeated hepatectomies after the initial operation for gastric GIST. The other patient had a synchronous liver metastasis and underwent total gastrectomy and partial resection of the liver as the initial treatment. Two of the 4 patients have received treatments 6 times, including hepatic resection, microwave coagulation therapy (MCT), radiofrequency ablation (RFA), or by imatinib. All 4 patients with hepatic metastases are alive after the first hepatectomy with a mean survival time of 64.8 months with or without imatinib treatment. None classified to very low risk and low risk groups by the NIH system showed liver metastasis, while 43% of the patients classified to the high risk showed liver metastasis. Conclusions: Repeated surgical and medical treatments for liver metastases from gastric GIST improve survival. Special attention should be paid to be the high risk group categorized by the NIH classification system.