1. Department of Gastroenterology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236‑0004, Japan
2. Department of Gastroenterology, Hepatobiliary and Pancreatic Medical Oncology Division, Kanagawa Cancer Center, Yokohama, Kanagawa 241‑8515, Japan
3. Department of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Kanagawa 241‑8515, Japan