1. Department of Gastrointestinal Oncology, Osaka International Cancer Institute, Osaka, Japan
2. Department of Gastroenterology, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
3. Department of Gastroenterology and Hepatology, Changi General Hospital, Singapore
4. Department of Gastroenterology and Hepatology, Gunma University Graduate School of Medicine, Maebashi, Japan