A 61-year-old man with increasing fatigue, early satiety, and nausea for 5 months vomited dark granular material yesterday. Endoscopy reveals a large ulcerated mass in the gastric fundus. Biopsies are taken and microscopically the mass is composed of spindle cells that are positive for c-Kit with immunohistochemical staining. Mitoses are frequent. Gastrectomy is performed, and the 10-cm circumscribed mass arises from the gastric wall. Which of the following therapies is most likely to be a useful adjunct in the treatment of his disease?
This gastrointestinal stromal tumor (GIST) is derived from the interstitial cell of Cajal, and hence of mesenchymal origin. Those arising in the stomach may be less aggressive than those arising in the intestine, but most are KIT positive and amenable to tyrosine kinase inhibitor therapy. Some GISTs may have mutations in platelet-derived growth factor receptor A (PDGFRA). Antibiotic therapy to obliterate Helicobacter pylori infection may be useful in treating MALTomas. Azathioprine and corticosteroids may be employed in treating inflammatory bowel disease, but the greatest risk for malignancy with inflammatory bowel disease is adenocarcinoma, particularly of the colon. Cyclophosphamide is a chemotherapy agent not employed in treating GISTs. Radiotherapy is not generally effective against mesenchymal malignancies.
Amoxicillin
Azathioprine
Cyclophosphamide
Imatinib
G.I.T.