The outcome of gastrointestinal stromal tumors (GISTs) after a surgical resection in our institute

Purpose. Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract arising from Cajal's cells and expressing c-kit. In a consensus report, the clinical behavior of GISTs was categorized into risk classes according to the tumor size and mitotic count. We analyzed the risk categories based on GIST patients who underwent a surgical resection at our institute during a period of 15 years. Methods. We evaluated the risk categories of GISTs and analyzed the outcome and risk categories retrospectively. We presented the MIB-1 score of the tumor instead of mitotic counts for the evaluation of cellular growth because of inaccuracies regarding the mitotic counts. Results. Patients were classified into 4 cases of very low risk, 11 of low risk, 8 of intermediate risk, and 5 of high risk. Four high-risk patients showed recurrence as either liver metastasis or peritoneal dissemination. In addition, local recurrence occurred in one low-risk and one intermediate-risk patient each. Conclusion. Our cases confirmed the correlation between the risk categories and the prognosis. A complete resection with sufficient margin must be confirmed even in low-risk cases to prevent local recurrence. Since high-risk patients showed poor prognosis, the adjuvant treatment with chemotherapeutic regimens must therefore be further studied for high-risk patients.