[1] Kansai Med Univ Hosp, Canc Treatment Ctr, Hirakata, Osaka, Japan
[2] Sano Hosp, Dept Gastrointestinal Canc Ctr, Kobe, Hyogo, Japan
[3] Saitama Med Univ, Dept Digest Tract & Gen Surg, Saitama Med Ctr, Saitama, Japan
[4] KKR Tonan Hosp, Med Oncol, Sapporo, Hokkaido, Japan
[5] Natl Hosp Org Nagoya Med Ctr, Dept Surg, Nagoya, Aichi, Japan
[6] Aizawa Hosp, Dept Chemotherapy, Matsumoto, Nagano, Japan
[7] Kitakyushu Gen Hosp, Dept Surg, Kitakyushu, Fukuoka, Japan
[8] Tokai Cent Hosp, Gifu, Japan
[9] Univ Tokyo, Sch Publ Hlth, Grad Sch Med, Dept Biostat, Tokyo, Japan
[10] Aichi Med Univ, Ctr Canc, Nagakute, Aichi, Japan