1. Department of Gastrointestinal Oncology & Endoscopy, National Cancer Center Hospital East, Kashiwa, Japan
2. Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan
3. Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan
4. Department of Gastroenterology, Saku Central Hospital, Nagano, Japan
5. Department of Diagnostic Imaging, Tochigi Cancer Center, Tochigi, Japan
6. TF Clinic, Tokyo, Japan
7. Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine, Tochigi, Japan