[New orientations in the management of advanced, metastatic gastrointestinal stromal tumors (GIST): combination of surgery and systemic therapy with imatinib in a case of primary gastric location].
Gastrointestinal stromal tumours (GIST) are rare neoplasms originating from connective tissue in the digestive tract with an incidence of less than 1% and account for most non-epithelial primitive digestive tumours. Metastasis diagnosed at the time of disease discovery confirms GIST malignancy. Kit protein, a trans-membrane tyrosine kinase receptor of staminal cells, is characteristically expressed by GIST. Most GIST have a mutation in the kit proto-oncogene. Resistance to conventional chemotherapy is commonly shown by malignant GIST. Most patients with advanced malignant GIST achieve clinical benefit with imatinib mesilate, an orally administered selective inhibitor of the tyrosine kinase receptor. We treated a 43-year-old male patient suffering from a gastric GIST diagnosed during a surgical emergency operation for peritonitis caused by gastric perforation. At the time of the first operation the patient had lost 10 kg body weight over the previous months and was seriously cachectic. During the emergency operation the perforation was sutured. The biopsy results showed the presence of CD1 17 (c-kit) and CD34 markers. A total body CT scan documented the substantial size of the gastric wall lesion, an increased volume of abdominal lymph nodes and compression of the splenic vein with alternative collateral circulation. The liver presented no less than 5 large metastases distributed in both the left and right lobes. There was also a pulmonary metastasis. Because of frequent spontaneous bleeding and starvation the patient was seriously anaemic. Considering the action mechanism of imatinib and the extent of the lesion we decided to perform a total gastrectomy procedure. At the time of the operation the stomach seemed to have a modified volume and shape: it appeared to be divided into two sacs, the larger and deeper of which was the original gastric cavity, while the superficial, smaller one seemed to be a protrusion of the organ. The stomach was indistinguishable from the spleen, the transverse colon and the distal pancreatic tract. The neoplasm was directly linked to the left liver and to the inferior diaphragmatic surface. We performed total gastrectomy and resection of the tail of the pancreas, the spleen, and the transverse colon all in one and the same session. The patient was discharged on postoperative day 8 and commenced imatinib therapy 30 days after the operation with 4 tablets per day. In the following months the patient repeated the CT scan to monitor the progressive volume reduction of the liver and lung lesions and a PET scan confirmed that the lesions were not active; the patient experienced a 13 kg body weight increase. One year after the operation the outcome appears to be lasting and the patient has tolerated the drug treatment well.