1 Division of Medical Oncology, Department of Internal Medicine, Hacettepe University Faculty of Medicine, Hacettepe University, Sihhiye, 06100, Ankara, Turkey. gunergurkan@yahoo.com.
2 Division of Medical Oncology, Department of Internal Medicine, Hacettepe University Faculty of Medicine, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.