RESUMO
BACKGROUND: Gastrointestinal stromal tumors are the most common mesenchymal neoplasms of the human gastrointestinal tract. OBJECTIVES: To review our accumulated experience using surgery to treat gastrointestinal stromal tumors. METHODS: We reviewed all patient charts and histological diagnoses of leiomyomas, leiomyosarcomas, leiomyoblastomas and schwannomas. Only tumors that displayed c-kit (CD117) immunopositivity were defined as GISTs. RESULTS: The study group comprised 40 female and 53 male patients (age 26-89 years); 40.8% of the tumors were classified as malignant, 39.8% as benign, and 19.4% as of uncertain malignancy. Fifty-six GISTs were located in the stomach (60.2%), 29 in the small bowel (31.2%), 4 in the duodenum (4.3%), 2 in the colon (2.1%) and 2 in the rectum (2.1%). Incidental GISTs were found in 23.7% of our patients. Mean overall survival time for malignant gastric GISTs was 102.6 months (95% confidence interval 74.2-131.1) as compared to 61.4 months mean overall survival for malignant small bowel GISTs (95% CI 35.7-87) (P = 0.262). The mean disease-free survival period for patients with malignant gastric GISTs was 97.5 months (95% CI 69.7-125.2) as compared to only 49.6 months (95% CI 27.4-71.7) for patients with small bowel malignant GISTs (P = 0.041). CONCLUSIONS: We found a high percentage of incidental GISTs. Gastric GISTs are more common than small bowel GISTs. Patients with malignant gastric GISTs have a significantly better prognosis than patients with malignant small bowel GISTs. A statistically significant correlation was found between age and malignant potential of the GIST.