[1] Natl Canc Res Inst, Carcinogenesis Div, Tokyo, Japan
[2] Wakayama Med Univ, Dept Internal Med 2, Wakayama, Japan
[3] Natl Canc Ctr, Carcinogenesis Div, Tokyo, Japan
[4] Natl Canc Ctr, Endoscopy Div, Tokyo, Japan
[5] Aichi Canc Ctr Res Inst, Div Oncol Pathol, Nagoya, Aichi, Japan
[6] Yamagata Univ, Dept Pathol, Sch Med, Yamagata, Japan