Gastrointestinal stromal tumors: A single center experience

Objective Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumor of the gastrointestinal (GI) tract. The aim of this retrospective study was to explore the characteristics, prognostic factors, and treatment results of GIST cases. Methods Clinical and pathological data of 35 GIST patients at our center between 2002 and 2015 were reviewed. Results Total of 18 (51.4%) were women and 17 (48.6%) were men, with median age of 54 years. Common site of tumor was stomach (48.6%). Abdominal pain (37.1%) was common clinical symptom. Risk group distribution was 8.6% low, 31.4% intermediate, and 60% high-risk cases. Mean follow-up period of the patients was 34 months. Low-risk GIST can be treated with surgery alone. Recurrence was observed in only 1 of 10 patients who received adjuvant treatment. All 6 patients in whom metastasis was determined were in high-risk group, and 4 of them had liver metastasis. Metastasis was not detected in any of the patients who had <5 mitoses per 50 high-power field (HPF), but in 5 of 12 patients who had >10 mitoses per 50 HPF, metastasis was determined. Metastasis did not correlate with site or size of tumor, but was related to high mitotic rate (p=0.015). Median overall survival of the patients was 79 months. Conclusion Low-risk GIST can be treated with surgery alone. Imatinib therapy significantly improves survival of high-risk or advanced-stage GIST patients. Metastasis did not correlate with site or size of tumor, but correlation with high mitotic rate was observed. © 2017, Turkish Society for Radiation Oncology.