Surgical Treatment of Gastric Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor is the most common mesenchymal tumor in the gastrointestinal tract and is most frequently developed in the stomach in the form of submucosal tumor. The incidence of gastric gastrointestinal stromal tumor is estimated to be as high as 25% of the population when all small and asymptomatic tumors are included. Because gastric gastrointestinal stromal tumor is not completely distinguished from other submucosal tumors, a surgical excisional biopsy is recommended for tumors >2 cm. The surgical principles of gastrointestinal stromal tumor are composed of an R0 resection with a normal mucosa margin, no systemic lymph node dissection, and avoidance of perforation, which results in peritoneal seeding even in cases with otherwise low risk profiles. Laparoscopic surgery has been indicated for gastrointestinal stromal tumors <5 cm, and the indication for laparoscopic surgery is expanded to larger tumors if the above mentioned surgical principles can be maintained. A simple exogastric resection and various transgastric resection techniques are used for gastrointestinal stromal tumors in favorable locations (the fundus, body, greater curvature side). For a lesion at the gastroesophageal junction in the posterior wall of the stomach, enucleation techniques have been tried preserve the organ's function. Those methods have a theoretical risk of seeding a ruptured tumor, but this risk has not been evaluated by well-designed clinical trials. While some clinical trials are still on-going, neoadjuvant imatinib is suggested when marginally unresectable or multiorgan resection is anticipated to reduce the extent of surgery and the chance of incomplete resection, rupture or bleeding.

Gastrointestinal stromal tumors

Gastrointestinal Stromal Tumor (GIST) is uncommon disease with only about 3,000 to 6,000 cases diagnosed annually. Tumors can occur in any sites in gastrointestinal tract, especially in stomach (60-70%) and small intestine (20-30%) and in large intestine and oesophagus, sometime in omentum, mesenterium, behind peritonaeum, etc. The disease is common in male from 40 to 80 years old. GIST is detected randomly during examinations such as endoscopy, X-ray or CT scan of stomach, large intestine. Tumors have two kinds of cell: lozenge cell (70%) and epithelial cell (30%). GIST is divided into 4 stages. Each stage has suitable treatments as chemical therapy, radio therapy, and targeted therapy. For metastatic GIST, tumors can be removed by surgery. The 5 years survival rate is 34% in removal tumors and is 10% in remained tumors