[1] Natl Canc Ctr, Div Gastrointestinal Med Oncol, Tokyo, Japan
[2] Natl Canc Ctr, Esophageal Surg Div, Tokyo, Japan
[3] Showa Univ, Sch Med, Dept Radiat Oncol, Tokyo, Japan
[4] Shikoku Canc Ctr Hosp, Dept Surg, Matsuyama, Ehime, Japan
[5] Hosp East, Natl Canc Ctr, Kashiwa, Chiba, Japan
[6] Osaka Int Canc Ctr, Osaka, Japan
[7] Toranomon Gen Hosp, Gastroenterol Surg, Tokyo, Japan
[8] Niigata Canc Ctr Hosp, Dept Gastroenterol Surg, Niigata, Japan
[9] Shizuoka Prefectural Gen Hosp, Shizuoka, Japan
[10] Kyoto Univ, Dept Surg, Kyoto, Japan
[11] Aichi Canc Ctr Hosp, Dept Gastroenterol Surg, Nagoya, Aichi, Japan
[12] Kobe Univ, Grad Sch Med, Dept Surg, Div Gastrointestinal Surg, Kobe, Hyogo, Japan
[13] Hiroshima City Asa Citizens Hosp, Dept Surg, Hiroshima, Japan
[14] Kyushu Natl Canc Ctr, Dept Gastroenterol Surg, Fukuoka, Fukuoka, Japan
[15] Kochi Hlth Sci Ctr, Dept Gastroenterol Surg, Kochi, Japan
[16] Natl Canc Ctr, Operat Off, Data Ctr, Japan Clin Oncol Grp, Tokyo, Japan
[17] Natl Canc Ctr, Operat Off, JCOG Data Ctr, Tokyo, Japan
[18] Keio Univ, Sch Med, Tokyo, Japan