[1] Kyoto Univ, Grad Sch Med, Dept Surg Gastroenterol, Kyoto, Japan
[2] Tokyo Med & Dent Univ, Dept Hepato Biliary Pancreat Surg, Grad Sch Med, Tokyo, Japan
[3] Kurume Univ, Sch Med, Dept Pathol, Kurume, Fukuoka 830, Japan
[4] Juntendo Univ, Sch Med, Dept Gastroenterol, Tokyo, Japan
[5] Univ Tokyo, Grad Sch Med, Dept Surg, Hepato Billiary Pancreat Surg Div, Tokyo, Japan
[6] Univ Tokyo, Sch Hlth Sci & Nursing, Dept Biostat, Tokyo, Japan
[7] Kanazawa Univ, Grad Sch Med, Dept Human Pathol, Kanazawa, Ishikawa, Japan
[8] Yamaguchi Univ, Sch Med, Dept Gastroenterol & Hepatol, Ube, Yamaguchi, Japan
[9] Univ Tokyo, Grad Sch Med, Dept Gastroenterol, Tokyo, Japan
[10] Natl Canc Ctr, Dept Diagnost Radiol, Tokyo, Japan