[1] Tochigi Canc Ctr, Dept Surg, Utsunomiya, Tochigi, Japan
[2] Natl Canc Ctr, Japan Clin Oncol Grp Data Ctr, Tokyo, Japan
[3] Natl Canc Ctr, Tokyo, Japan
[4] Natl Canc Ctr Hosp East, Div Colorectal Surg, Kashiwa, Chiba, Japan
[5] Shizuoka Canc Ctr Hosp, Div Colon & Rectal Surg, Shizuoka, Japan
[6] Aichi Canc Ctr Hosp, Dept Surg Gastroenterol, Aichi, Japan
[7] Osaka Med Ctr Canc & Cardiovascular Dis, Dept Surg, Osaka, Japan
[8] Yokohama City Univ, Gastroenterol Ctr, Med Ctr, Yokohama, Kanagawa, Japan
[9] Okayama Saiseikai Gen Hosp, Okayama, Japan
[10] Kanagawa Canc Ctr, Gastrointestinal Surg, Yokohama, Kanagawa, Japan
[11] Kyoto Med Ctr, Kyoto, Japan
[12] Ishikawa Prefectural Cent Hosp, Gastroenterol Surg, Kanazawa, Ishikawa, Japan
[13] Tokyo Med Univ, Dept Gastrointestinal & Pediat Surg, Tokyo, Japan
[14] Suita Municipal Hosp, Dept Surg, Suita, Osaka, Japan
[15] Kurume Univ, Dept Surg, Kurume, Fukuoka, Japan
[16] Chiba Canc Ctr, Chiba, Japan
[17] Toho Univ, Tokyo, Japan
[18] Hosp Imperial Household, Tokyo, Japan