Kenta Hamada1,2, Noriya Uedo1, Hitoshi Tanishita3. 1. Department of Gastrointestinal Oncology, Osaka International Cancer Institute, Osaka, Japan. 2. Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. 3. Department of Gastroenterology, Ikeda Hospital, Higashiosaka, Japan.