Clinical experience in diagnosis and treatment of malignant gastrointestinal stromal tumors.

This study investigated the clinical pathologic character of malignant gastrointestinal stromal tumors (MGIST), their treatment with surgery, and evaluated the efficacy of imatinib postoperation. A total of 68 MGIST patients were enrolled. Of these, 27 patients underwent imatinib auxiliary therapy (treatment group) and 41 underwent imatinib therapy (control group). The therapeutic effects on the two groups were compared using χ(2) test analysis after follow-up of two years. The expressions of CD117, CD34, S100, Vimentin, and alpha smooth-muscle actin (SMA) were detected by immunohistochemistry methods. Of the 68 cases, 28 showed potential MGIST, whereas 40 had MGIST. Haemorrhagia or necrosis, abundant cell, manifest heteromorphism, and caryocinesia were observed in varying degrees. The positive rates of CD117, CD34, Vimentin, S100, and SMA were 89.7% (61/62), 88.2% (60/62), 73.5% (50/62), 41.1% (28/62) and 25.0% (17/62), respectively. The recurrence rate in the treatment group was significantly lower than that in the control group (p < 0.01). We concluded that CD117 and CD34 may be the most valuable markers in the diagnosis of MGIST, and the diagnosis of MGIST depends on the pathology. Surgery is a far better approach in the treatment of such patients, and imatinib is the more efficient target drug in preventing recurrence and metastasis.