[1] Univ Tsukuba, Fac Med, Dept Gastroenterol, Clin Med, 1-1-1 Tennodai, Tsukuba, Ibaraki 3058575, Japan
[2] Natl Canc Ctr Hosp East, Dept Gastroenterol & Gastrointestinal Oncol, Kashiwa, Japan
[3] Osaka Med & Pharmaceut Univ, Canc Chemotherapy Ctr, Takatsuki, Japan
[4] Komagome Hosp, Tokyo Metropolitan Canc & Infect Dis Ctr, Dept Surg, Bunkyo, Japan
[5] Ishinomaki Red Cross Hosp, Dept Clin Oncol, Ishinomaki, Japan
[6] Kurume Univ, Sch Med, Dept Surg, Fukuoka, Japan
[7] Kansai Rosai Hosp, Dept Surg, Amagasaki, Hyogo, Japan
[8] Osaka Int Canc Inst, Dept Clin Oncol, Osaka, Japan
[9] Shiga Univ Med Sci, Div Gastrointestinal Surg, Otsu, Shiga, Japan
[10] Shizuoka Canc Ctr, Div Gastrointestinal Oncol, Nagaizumi, Japan
[11] Natl Canc Ctr Hosp, Gastrointestinal Med Oncol Div, Chuo, Japan
[12] Kagawa Univ, Fac Med, Dept Clin Oncol, Takamatsu, Japan
[13] Natl Hosp Org, Osaka Natl Hosp, Dept Gastroenterol & Hepatol, Osaka, Japan
[14] Toranomon Gen Hosp, Dept Med Oncol, Minato, Japan
[15] Kyushu Univ, Grad Sch Med Sci, Dept Comprehens Oncol & Social Med, Fukuoka, Japan
[16] Himeji Red Cross Hosp, Dept Med Oncol, Himeji, Japan
[17] Hokkaido Univ Hosp, Div Canc Ctr, Sapporo, Japan
[18] Natl Hosp Org, Nagoya Med Ctr, Dept Surg, Nagoya, Japan
[19] Nakadori Gen Hosp, Gastroenterol Surg, Akita, Japan
[20] Juntendo Univ, Dept Med Oncol, Bunkyo, Japan
[21] NHO Kyushu Canc Ctr, Dept Gastrointestinal & Med Oncol, Fukuoka, Japan
[22] Ishikawa Prefectural Cent Hosp, Dept Med Oncol, Kanazawa, Japan
[23] Kitasato Univ, Sch Med, Dept Lower Gastrointestinal Surg, Sagamihara, Japan
[24] Kyoto Univ, Grad Sch Med, Dept Therapeut Oncol, Kyoto, Japan
[25] Kochi Hlth Sci Ctr, Dept Clin Oncol, Kochi, Japan
[26] Kurashiki Cent Hosp, Dept Hepatol & Gastroenterol, 1-1-1 Miwa, Kurashiki, Okayama 7100052, Japan