1. Department of Gastroenterology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
2. Department of Gastroenterology, Houjie Hospital Affiliated to Guangdong Medical College, Dongguan, China
3. Department of General Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
4. Department of Oncology, Guangzhou Red Cross Hospital, Medical College, Jinan University, Guangzhou, China