[1] Kyoto Univ, Dept Gastroenterol & Hepatol, Grad Sch Med, Sakyo Ku, Kyoto 6068507, Japan
[2] Kyoto Univ, Dept Multidisciplinary Canc Treatment, Grad Sch Med, Kyoto 6068507, Japan
[3] Natl Canc Ctr Hosp E, Div Gastrointestinal Oncol & Endoscopy, Kashiwa, Chiba, Japan
[4] Chiba Canc Ctr, Div Clin Res Promot, Chiba 2608717, Japan