[1] NTT Med Ctr Tokyo, Dept Gastroenterol, Shinagawa Ku, Tokyo 1418625, Japan
[2] Univ Tokyo, Grad Sch Med, Dept Gastroenterol, Bunkyo Ku, Tokyo 1138655, Japan
[3] NTT Med Ctr Tokyo, Dept Prevent Med, Shinagawa Ku, Tokyo 1418625, Japan
[4] NTT Med Ctr Tokyo, Dept Pathol, Shinagawa Ku, Tokyo 1418625, Japan
[5] Univ Tokyo, Grad Sch Med, Dept Endoscopy & Endoscop Surg, Bunkyo Ku, Tokyo 1138655, Japan