1. Division of Gastroenterohepatology, Department of Internal Medicine, Hasan Sadikin General Hospital, Faculty of Medicine, University of Padjadjaran, Bandung 40161, Indonesia
2. Mochtar Riady Comprehensive Cancer Center, Siloam Hospitals, Jakarta 12930, Indonesia
3. Division of Gastroenterology, Department of Internal Medicine, Cipto Mangunkusumo National Central Hospital, Faculty of Medicine, University of Indonesia, Jakarta 10430, Indonesia