Aims: Because gastric GISTs show variable clinical behavior, we reviewed our experience with primary gastric GISTs after surgical treatment and imatinib mesylate treatment for advanced disease.
Methods: Between December 1995 and December 2005, 111 patients who underwent surgical treatment for primary gastric GISTs were enrolled in this study. Patients were grouped according to the risk assessment classification, and clinicopathological features, tumor recurrence and patient survival were assessed.
Results: One patient was included in the very low risk group, 35 in the low risk group, 31 in the intermediate risk group and 44 in the high-risk group. All patients with very low, low and intermediate risk GISTs and 70% of patients with high risk GISTs underwent R0 resection. While there was no recurrence or metastasis in patients with very low, low and intermediate risk GISTs, 23% of those with high risk GISTs showed a distant metastasis at diagnosis and 35% of these patients had a recurrence after R0 resection. The overall 5-year survival rate of the high risk patients was 77.1%. Nineteen patients received imatinib mesylate therapy due to an incomplete resection or recurrence; 7 with no measurable lesion at the CT scan by a local tumor control showed no tumor progression after imatinib mesylate therapy, however, 12 patients with measurable lesions showed variable clinical courses after treatment. The overall 5-year survival rate of 19 patients with imatinib mesylate treatment was 80.0%.
Conclusions: The clinical outcome of the very low, low and intermediate risk gastric GISTs was excellent, while high risk gastric GISTs had a high rate of recurrence and therefore a less favorable outcome. A complete resection is the most important treatment for cure; however imatinib mesylate treatment may improve the clinical outcome of the patients with metastatic or recurrent gastric GISTs.