[1] Aichi Canc Ctr Hosp, Dept Clin Oncol, Nagoya, Aichi 464, Japan
[2] Natl Canc Ctr, Tokyo 104, Japan
[3] Japanese Fdn Canc Res, Canc Inst Hosp, Dept Gastroenterol, Tokyo, Japan
[4] Natl Hosp Org Shikoku Canc Ctr, Dept Gastroenterol, Matsuyama, Ehime, Japan
[5] Natl Hosp Org Kyoto Med Ctr, Dept Med Oncol, Kyoto, Japan
[6] Chiba Canc Ctr, Div Gastroenterol, Chiba 2608717, Japan
[7] Japanese Red Cross Kitami Hosp, Dept Surg, Kitami, Hokkaido, Japan
[8] Kyushu Natl Canc Ctr, Dept Gastrointestinal & Med Oncol, Fukuoka, Japan
[9] Hyogo Canc Ctr, Dept Gastrointestinal & Hepato Biliary Oncol, Akashi, Hyogo, Japan
[10] Southern Tohoku Gen Hosp, Dept Surg, Koriyama, Fukushima, Japan
[11] Natl Hosp Org Nagoya Med Ctr, Dept Surg, Nagoya, Aichi, Japan
[12] Osaka City Gen Hosp, Dept Clin Oncol, Osaka, Japan
[13] Hokkaido Canc Ctr, Dept Gastroenterol, Sapporo, Hokkaido, Japan
[14] Natl Kyushu Med Ctr, Dept Surg, Fukuoka, Japan
[15] Teikyo Univ, Sch Med, Kawasaki, Kanagawa, Japan