[1] Hokkaido Univ Hosp, Ctr Canc, Dept Canc Chemotherapy, Sapporo, Hokkaido 060, Japan
[2] Hokkaido Univ Hosp, Dept Gastroenterol & Hepatol, Sapporo, Hokkaido 060, Japan
[3] Toyama Univ, Fac Med, Dept Gastroenterol & Hematol, Toyama 930, Japan
[4] Sapporo City Gen Hosp, Dept Gastroenterol, Sapporo, Hokkaido, Japan
[5] Japanese Red Cross Akita Hosp, Dept Med Oncol, Akita, Japan
[6] Hokkaido Gastroenterol Hosp, Sapporo, Hokkaido, Japan
[7] Japanese Red Cross Kitami Hosp, Dept Gastroenterol, Kitami, Hokkaido, Japan
[8] Hakodate Municipal Hosp, Dept Gastroenterol, Hakodate, Hokkaido, Japan
[9] Tonan Hosp, Dept Med Oncol, Sapporo, Hokkaido, Japan
[10] Hirosaki Univ, Grad Sch Med, Dept Med Oncol, Hirosaki, Aomori, Japan
[11] Tomakomai City Hosp, Dept Gastroenterol, Tomakomai, Japan
[12] Niigata City Gen Hosp, Niigata, Japan
[13] Abashiri Kosei Gen Hosp, Dept Gastroenterol, Abashiri, Japan
[14] Tomakomai Nisshou Hosp, Dept Internal Med, Tomakomai, Japan
[15] Hokkaido Canc Ctr, Dept Gastroenterol, Sapporo, Hokkaido, Japan
[16] Kushiro Rosai Hosp, Dept Internal Med, Kushiro, Hokkaido, Japan
[17] Kumamoto City Hosp, Dept Surg, Kumamoto, Japan
[18] Nagasaki Univ, Dept Gastroenterol & Hepatol, Grad Sch Biomed Sci, Nagasaki 852, Japan
[19] Misawa City Hosp, Misawa, Japan