[1] Niigata Canc Ctr Hosp, Dept Surg, Chuo Ku, Niigata 9518566, Japan
[2] Niigata Univ, Med & Dent Hosp, Dept Med Informat, Niigata, Japan
[3] Natl Hosp Org Tokyo Med Ctr, Dept Surg, Tokyo, Japan
[4] Osaka Med Ctr Canc & Cardiovasc Dis, Dept Surg, Osaka, Japan
[5] Natl Canc Ctr, Dept Surg, Tokyo, Japan
[6] Nagoya Univ, Sch Med, Dept Surg, Nagoya, Aichi 466, Japan
[7] Kyushu Univ, Grad Sch Med Sci, Dept Surg & Sci, Fukuoka 812, Japan
[8] Univ Tokyo, Grad Sch Med, Dept Gastrointestinal Surg, Tokyo 113, Japan
[9] Sakai City Hosp, Dept Surg, Sakai, Osaka, Japan
[10] Natl Canc Ctr, Endoscopy Div, Tokyo, Japan
[11] Shizuoka Canc Ctr Hosp, Endoscopy Div, Shizuoka, Japan
[12] Kitasato Univ, Sch Med, Dept Gastroenterol, Kanagawa, Japan
[13] Showa Gen Hosp, Dept Surg, Tokyo, Japan