TURKISH JOURNAL OF ONCOLOGY 2017 , Vol 32 , Num 1
Gastrointestinal Stromal Tumors: A Single Center Experience
Nilgün YILDIRIM1,Melih ŞIMŞEK2,Mehmet Naci ALDEMIR3,Mehmet BILICI,Salim BAŞOL TEKIN2
1Department of Medical Oncology, Dr. Ersin Arslan Training and Research Hospital, Gaziantep-Turkey
2Department of Medical Oncology, Atatürk University Faculty of Medicine, Erzurum-Turkey
3Department of Medical Oncology, Erzincan University Faculty of Medicine, Erzincan-Turkey
DOI : 10.5505/tjo.2017.1523 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. Keywords : Gastrointestinal stromal tumors; prognosis; survival; treatment