Gastrointestinal stromal tumors: diagnosis and treatment

Abstract

Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms of the digestive tract. They originate from the interstitial cells of Cajal and are characterized by the overexpression of KIT protein (tyrosine kinase). Their prognosis has improved significantly with the discovery of imatinib mesylate for advanced GIST treatment.

Methods: We carried out a retrospective, descriptive study of GISTs diagnosed in our center during the past 5 years. We excluded patients with incidental diagnoses in the context of other pathologies because GIST did not affect outcome or prognosis. The variables studied were clinical characteristics, location, size, imaging techniques, resectability, neoadjuvant imatinib, surgical technique, histology, immunohistochemistry, prognostic classification of Fletcher, morbidity, monitoring, and disease-free and overall survival.

Results: Nineteen patients were diagnosed (14 males/5 females) with a mean age of 63 years (range: 30-84 years). Diagnosis was incidental in eight patients (42%). Tumor location of the remaining 11 patients (58%) was six tumors of the small intestine (55%), four gastric (36%) and one rectal (9%). Predominant gastrointestinal bleeding and anemia were diagnosed mainly by abdominal computed tomography (CT). At diagnosis, nine patients were considered resectable with radical intent (82%) and the other two patients (18%) received neoadjuvant treatment with a favorable response after 6 months. Three patients were treated with imatinib after surgery (33%). Median survival was 34 months (range: 5-58 months).

Conclusions: Diagnosis of GIST is often incidental. The predominant clinical symptom is usually gastrointestinal bleeding and anemia and the most widely used imaging test is CT. Treatment is surgical unless advanced GIST is diagnosed, which will be treated with imatinib mesylate neoadjuvant therapy. A multidisciplinary approach to this pathology is essential, a fact that affects prognosis and patient survival.