1. Department of Medicine, College of Medicine, King Saud University, Riyadh 12372, Saudi Arabia
2. Division of Hematology/Oncology, Department of Medicine, King Khalid University Hospital, College of Medicine, King Saud University Medical City, Riyadh 12372, Saudi Arabia
3. Department of Medical Oncology, South Egypt Cancer Institute, Assiut University, Assiut 71516, Egypt
4. Department of Oncology, Division of Radiation Oncology, King Khalid University Hospital, College of Medicine, King Saud University Medical City, Riyadh 12372, Saudi Arabia
5. Clinical Oncology Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt