1. Department of General Surgery, University of Health Sciences, Ankara Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
2. Department of General Surgery, University of Health Sciences, Gulhane Training and Research Hospital, Ankara, Turkey
3. Department of Medical and Surgical Research, University of Health Sciences, Hacettepe University, Ankara, Turkey
4. Department of General Surgery, University of Health Sciences, Ankara Kecioren Training and Research Hospital, Ankara, Turkey
5. Department of Basic Oncology, Cancer Institute, Hacettepe University, Ankara, Turkey